# Cart Instructions

Instructions used to create the checkout.

```jsx
import {
  Banner,
  Button,
  useApplyDiscountCodeChange,
  useInstructions,
  reactExtension,
} from '@shopify/ui-extensions-react/checkout';

export default reactExtension(
  'purchase.checkout.block.render',
  () => <Extension />,
);

function Extension() {
  const applyDiscountCodeChange =
    useApplyDiscountCodeChange();
  const instructions = useInstructions();

  if (
    instructions.discounts.canUpdateDiscountCodes
  ) {
    return (
      <Button
        onPress={() =>
          applyDiscountCodeChange({
            type: 'addDiscountCode',
            code: 'FREE_SHIPPING',
          })
        }
      >
        Apply your loyalty discount
      </Button>
    );
  } else {
    return (
      <Banner status="warning">
        Loyalty discounts are unavailable
      </Banner>
    );
  }
}

```

```js
import {
  extension,
  Banner,
  Button,
} from '@shopify/ui-extensions/checkout';

export default extension(
  'purchase.checkout.block.render',
  (root, api) => {
    if (
      api.instructions.current.discounts
        .canUpdateDiscountCodes
    ) {
      root.appendChild(
        root.createComponent(
          Button,
          {
            onPress: () =>
              api.applyDiscountCodeChange({
                type: 'addDiscountCode',
                code: 'FREE_SHIPPING',
              }),
          },
          'Apply your loyalty discount',
        ),
      );
    } else {
      root.appendChild(
        root.createComponent(
          Banner,
          {},
          'Loyalty discounts are unavailable',
        ),
      );
    }
  },
);

```

## StandardApi

The base API object provided to `purchase` extension targets.

### Docs_Standard_CartInstructionsApi

### instructions

value: `StatefulRemoteSubscribable<CartInstructions>`

The cart instructions used to create the checkout and possibly limit extension capabilities.

These instructions should be checked prior to performing any actions that may be affected by them.

For example, if you intend to add a discount code via the `applyDiscountCodeChange` method, check `discounts.canUpdateDiscountCodes` to ensure it's supported in this checkout.

> Caution: As of version `2024-07`, UI extension code must check for instructions before calling select APIs in case those APIs are not available.  See the [update guide](https://shopify.dev/docs/api/checkout-ui-extensions/instructions-update) for more information.

### CartInstructions

### attributes

value: `AttributesCartInstructions`

Cart instructions related to cart attributes.

### delivery

value: `DeliveryCartInstructions`

Cart instructions related to delivery.

### discounts

value: `DiscountsCartInstructions`

Cart instructions related to discounts.

### lines

value: `CartLinesCartInstructions`

Cart instructions related to cart lines.

### metafields

value: `MetafieldsCartInstructions`

Cart instructions related to metafields.

### notes

value: `NotesCartInstructions`

Cart instructions related to notes.

### AttributesCartInstructions

### canUpdateAttributes

value: `boolean`

Indicates whether or not cart attributes can be updated.

### DeliveryCartInstructions

### canSelectCustomAddress

value: `boolean`

Indicates whether a buyer can select a custom address.

When true, this implies extensions can update the delivery address.

### DiscountsCartInstructions

### canUpdateDiscountCodes

value: `boolean`

Indicates whether or not discount codes can be updated.

### CartLinesCartInstructions

### canAddCartLine

value: `boolean`

Indicates whether or not new cart lines can be added.

### canRemoveCartLine

value: `boolean`

Indicates whether or not cart lines can be removed.

### canUpdateCartLine

value: `boolean`

Indicates whether or not cart lines can be updated.

### MetafieldsCartInstructions

### canDeleteCartMetafield

value: `boolean`

Indicates whether or not cart metafields can be deleted.

### canSetCartMetafields

value: `boolean`

Indicates whether or not cart metafields can be added or updated.

### NotesCartInstructions

### canUpdateNote

value: `boolean`

Indicates whether or not notes can be updated.

## Related

- [Targets](https://shopify.dev/docs/api/checkout-ui-extensions/targets)
- [Components](https://shopify.dev/docs/api/checkout-ui-extensions/components)
- [Configuration](https://shopify.dev/docs/api/checkout-ui-extensions/configuration)
- [Tutorials](/apps/checkout)

## Examples

Instructions used to create the checkout.



      Check `instructions.attributes.canUpdateAttributes` before calling `applyAttributeChange()`.
      

```jsx
import {
  Banner,
  Button,
  useApplyAttributeChange,
  useInstructions,
  reactExtension,
} from '@shopify/ui-extensions-react/checkout';

export default reactExtension(
  'purchase.checkout.block.render',
  () => <Extension />,
);

function Extension() {
  const applyAttributeChange =
    useApplyAttributeChange();
  const instructions = useInstructions();

  if (
    instructions.attributes.canUpdateAttributes
  ) {
    return (
      <Button
        onPress={() =>
          applyAttributeChange({
            type: 'updateAttribute',
            key: 'loyaltyPoints',
            value: '100',
          })
        }
      >
        Apply 100 loyalty points
      </Button>
    );
  } else {
    return (
      <Banner status="warning">
        Loyalty points are unavailable
      </Banner>
    );
  }
}

```

```js
import {
  extension,
  Banner,
  Button,
} from '@shopify/ui-extensions/checkout';

export default extension(
  'purchase.checkout.block.render',
  (root, api) => {
    if (
      api.instructions.current.attributes
        .canUpdateAttributes
    ) {
      root.appendChild(
        root.createComponent(
          Button,
          {
            onPress: () =>
              api.applyAttributeChange({
                type: 'updateAttribute',
                key: 'loyaltyPoints',
                value: '100',
              }),
          },
          'Apply 100 loyalty points',
        ),
      );
    } else {
      root.appendChild(
        root.createComponent(
          Banner,
          {},
          'Loyalty points are unavailable',
        ),
      );
    }
  },
);

```



      Check `instructions.delivery.canSelectCustomAddress` before calling `applyShippingAddressChange()`. When `true`, this instruction implies that extensions can change the shipping address.
      

```jsx
import {
  Banner,
  Button,
  useApplyShippingAddressChange,
  useInstructions,
  reactExtension,
} from '@shopify/ui-extensions-react/checkout';

export default reactExtension(
  'purchase.checkout.block.render',
  () => <Extension />,
);

function Extension() {
  const applyShippingAddressChange =
    useApplyShippingAddressChange();
  const instructions = useInstructions();

  if (
    instructions.delivery.canSelectCustomAddress
  ) {
    return (
      <Button
        onPress={() =>
          applyShippingAddressChange({
            type: 'updateShippingAddress',
            address: {
              zip: '90201',
            },
          })
        }
      >
        Change your postal code
      </Button>
    );
  } else {
    return (
      <Banner status="warning">
        Shipping address cannot be modified
      </Banner>
    );
  }
}

```

```js
import {
  extension,
  Banner,
  Button,
} from '@shopify/ui-extensions/checkout';

export default extension(
  'purchase.checkout.block.render',
  (root, api) => {
    if (
      api.instructions.current.delivery
        .canSelectCustomAddress
    ) {
      root.appendChild(
        root.createComponent(
          Button,
          {
            onPress: () =>
              api.applyShippingAddressChange({
                type: 'updateShippingAddress',
                address: {
                  zip: '90201',
                },
              }),
          },
          'Change your postal code',
        ),
      );
    } else {
      root.appendChild(
        root.createComponent(
          Banner,
          {},
          'Shipping address cannot be modified',
        ),
      );
    }
  },
);

```



      Check `instructions.discounts.canUpdateDiscountCodes` before calling `applyDiscountCodeChange()`.
      

```jsx
import {
  Banner,
  Button,
  useApplyDiscountCodeChange,
  useInstructions,
  reactExtension,
} from '@shopify/ui-extensions-react/checkout';

export default reactExtension(
  'purchase.checkout.block.render',
  () => <Extension />,
);

function Extension() {
  const applyDiscountCodeChange =
    useApplyDiscountCodeChange();
  const instructions = useInstructions();

  if (
    instructions.discounts.canUpdateDiscountCodes
  ) {
    return (
      <Button
        onPress={() =>
          applyDiscountCodeChange({
            type: 'addDiscountCode',
            code: 'FREE_SHIPPING',
          })
        }
      >
        Apply your loyalty discount
      </Button>
    );
  } else {
    return (
      <Banner status="warning">
        Loyalty discounts are unavailable
      </Banner>
    );
  }
}

```

```js
import {
  extension,
  Banner,
  Button,
} from '@shopify/ui-extensions/checkout';

export default extension(
  'purchase.checkout.block.render',
  (root, api) => {
    if (
      api.instructions.current.discounts
        .canUpdateDiscountCodes
    ) {
      root.appendChild(
        root.createComponent(
          Button,
          {
            onPress: () =>
              api.applyDiscountCodeChange({
                type: 'addDiscountCode',
                code: 'FREE_SHIPPING',
              }),
          },
          'Apply your loyalty discount',
        ),
      );
    } else {
      root.appendChild(
        root.createComponent(
          Banner,
          {},
          'Loyalty discounts are unavailable',
        ),
      );
    }
  },
);

```



      Check `instructions.lines.canAddCartLine` or `instructions.lines.canRemoveCartLine` or `instructions.lines.canUpdateCartLine` before calling `applyCartLinesChange()`.
      

```jsx
import {
  Banner,
  Button,
  useApplyCartLinesChange,
  useInstructions,
  reactExtension,
} from '@shopify/ui-extensions-react/checkout';

export default reactExtension(
  'purchase.checkout.block.render',
  () => <Extension />,
);

function Extension() {
  const applyCartLinesChange =
    useApplyCartLinesChange();
  const instructions = useInstructions();

  if (instructions.lines.canAddCartLine) {
    return (
      <Button
        onPress={() =>
          applyCartLinesChange({
            type: 'addCartLine',
            merchandiseId:
              'gid://shopify/product/1234',
            quantity: 1,
          })
        }
      >
        Add a free gift to your order
      </Button>
    );
  } else {
    return (
      <Banner status="warning">
        The products in your cart cannot be
        modified
      </Banner>
    );
  }
}

```

```js
import {
  extension,
  Banner,
  Button,
} from '@shopify/ui-extensions/checkout';

export default extension(
  'purchase.checkout.block.render',
  (root, api) => {
    if (
      api.instructions.current.lines
        .canAddCartLine
    ) {
      root.appendChild(
        root.createComponent(
          Button,
          {
            onPress: () =>
              api.applyCartLinesChange({
                type: 'addCartLine',
                merchandiseId:
                  'gid://shopify/product/1234',
                quantity: 1,
              }),
          },
          'Add a free gift to your order',
        ),
      );
    } else {
      root.appendChild(
        root.createComponent(
          Banner,
          {},
          'The products in your cart cannot be modified',
        ),
      );
    }
  },
);

```



      Check `instructions.metafields.canSetCartMetafields` or `instructions.metafields.canDeleteCartMetafields` before calling `applyMetafieldChange()` if you are working with cart metafields.
      

```jsx
import {
  Banner,
  Button,
  useApplyMetafieldChange,
  useInstructions,
  reactExtension,
} from '@shopify/ui-extensions-react/checkout';

export default reactExtension(
  'purchase.checkout.block.render',
  () => <Extension />,
);

function Extension() {
  const applyMetafieldChange =
    useApplyMetafieldChange();
  const instructions = useInstructions();

  if (
    instructions.metafields.canSetCartMetafields
  ) {
    return (
      <Button
        onPress={() =>
          applyMetafieldChange({
            type: 'updateCartMetafield',
            metafield: {
              namespace: 'loyalty',
              key: 'loyaltyPoints',
              value: '100',
              type: 'string',
            },
          })
        }
      >
        Apply 100 loyalty points
      </Button>
    );
  } else {
    return (
      <Banner status="warning">
        Loyalty points are unavailable
      </Banner>
    );
  }
}

```

```js
import {
  extension,
  Banner,
  Button,
} from '@shopify/ui-extensions/checkout';

export default extension(
  'purchase.checkout.block.render',
  (root, api) => {
    if (
      api.instructions.current.metafields
        .canSetCartMetafields
    ) {
      root.appendChild(
        root.createComponent(
          Button,
          {
            onPress: () =>
              api.applyMetafieldChange({
                type: 'updateCartMetafield',
                metafield: {
                  namespace: 'loyalty',
                  key: 'loyaltyPoints',
                  value: '100',
                  type: 'string',
                },
              }),
          },
          'Apply 100 loyalty points',
        ),
      );
    } else {
      root.appendChild(
        root.createComponent(
          Banner,
          {},
          'Loyalty points are unavailable',
        ),
      );
    }
  },
);

```



      Check `instructions.notes.canUpdateNote` before calling `applyNoteChange()`.
      

```jsx
import {
  Banner,
  Button,
  useApplyNoteChange,
  useInstructions,
  reactExtension,
} from '@shopify/ui-extensions-react/checkout';

export default reactExtension(
  'purchase.checkout.block.render',
  () => <Extension />,
);

function Extension() {
  const applyNoteChange = useApplyNoteChange();
  const instructions = useInstructions();

  if (instructions.notes.canUpdateNote) {
    return (
      <Button
        onPress={() =>
          applyNoteChange({
            type: 'updateNote',
            note: 'Please include a free gift.',
          })
        }
      >
        Include a free gift with your order
      </Button>
    );
  } else {
    return (
      <Banner status="warning">
        Free gifts cannot be added to this order
      </Banner>
    );
  }
}

```

```js
import {
  extension,
  Banner,
  Button,
} from '@shopify/ui-extensions/checkout';

export default extension(
  'purchase.checkout.block.render',
  (root, api) => {
    if (
      api.instructions.current.notes.canUpdateNote
    ) {
      root.appendChild(
        root.createComponent(
          Button,
          {
            onPress: () =>
              api.applyNoteChange({
                type: 'updateNote',
                note: 'Please include a free gift.',
              }),
          },
          'Include a free gift with your order',
        ),
      );
    } else {
      root.appendChild(
        root.createComponent(
          Banner,
          {},
          'Free gifts cannot be added to this order',
        ),
      );
    }
  },
);

```

## useInstructions

Returns the cart instructions used to create the checkout and possibly limit extension capabilities.

### UseInstructionsGeneratedType

Returns the cart instructions used to create the checkout and possibly limit extension capabilities.

#### Returns: CartInstructions
export function useInstructions<
  Target extends RenderExtensionTarget = RenderExtensionTarget,
>(): CartInstructions {
  return useSubscription(useApi<Target>().instructions);
}


### CartInstructions

### attributes

value: `AttributesCartInstructions`

Cart instructions related to cart attributes.

### delivery

value: `DeliveryCartInstructions`

Cart instructions related to delivery.

### discounts

value: `DiscountsCartInstructions`

Cart instructions related to discounts.

### lines

value: `CartLinesCartInstructions`

Cart instructions related to cart lines.

### metafields

value: `MetafieldsCartInstructions`

Cart instructions related to metafields.

### notes

value: `NotesCartInstructions`

Cart instructions related to notes.

### AttributesCartInstructions

### canUpdateAttributes

value: `boolean`

Indicates whether or not cart attributes can be updated.

### DeliveryCartInstructions

### canSelectCustomAddress

value: `boolean`

Indicates whether a buyer can select a custom address.

When true, this implies extensions can update the delivery address.

### DiscountsCartInstructions

### canUpdateDiscountCodes

value: `boolean`

Indicates whether or not discount codes can be updated.

### CartLinesCartInstructions

### canAddCartLine

value: `boolean`

Indicates whether or not new cart lines can be added.

### canRemoveCartLine

value: `boolean`

Indicates whether or not cart lines can be removed.

### canUpdateCartLine

value: `boolean`

Indicates whether or not cart lines can be updated.

### MetafieldsCartInstructions

### canDeleteCartMetafield

value: `boolean`

Indicates whether or not cart metafields can be deleted.

### canSetCartMetafields

value: `boolean`

Indicates whether or not cart metafields can be added or updated.

### NotesCartInstructions

### canUpdateNote

value: `boolean`

Indicates whether or not notes can be updated.

## Related

- [Targets](https://shopify.dev/docs/api/checkout-ui-extensions/targets)
- [Components](https://shopify.dev/docs/api/checkout-ui-extensions/components)
- [Configuration](https://shopify.dev/docs/api/checkout-ui-extensions/configuration)
- [Tutorials](/apps/checkout)

## Examples

Instructions used to create the checkout.



      Check `instructions.attributes.canUpdateAttributes` before calling `applyAttributeChange()`.
      

```jsx
import {
  Banner,
  Button,
  useApplyAttributeChange,
  useInstructions,
  reactExtension,
} from '@shopify/ui-extensions-react/checkout';

export default reactExtension(
  'purchase.checkout.block.render',
  () => <Extension />,
);

function Extension() {
  const applyAttributeChange =
    useApplyAttributeChange();
  const instructions = useInstructions();

  if (
    instructions.attributes.canUpdateAttributes
  ) {
    return (
      <Button
        onPress={() =>
          applyAttributeChange({
            type: 'updateAttribute',
            key: 'loyaltyPoints',
            value: '100',
          })
        }
      >
        Apply 100 loyalty points
      </Button>
    );
  } else {
    return (
      <Banner status="warning">
        Loyalty points are unavailable
      </Banner>
    );
  }
}

```

```js
import {
  extension,
  Banner,
  Button,
} from '@shopify/ui-extensions/checkout';

export default extension(
  'purchase.checkout.block.render',
  (root, api) => {
    if (
      api.instructions.current.attributes
        .canUpdateAttributes
    ) {
      root.appendChild(
        root.createComponent(
          Button,
          {
            onPress: () =>
              api.applyAttributeChange({
                type: 'updateAttribute',
                key: 'loyaltyPoints',
                value: '100',
              }),
          },
          'Apply 100 loyalty points',
        ),
      );
    } else {
      root.appendChild(
        root.createComponent(
          Banner,
          {},
          'Loyalty points are unavailable',
        ),
      );
    }
  },
);

```



      Check `instructions.delivery.canSelectCustomAddress` before calling `applyShippingAddressChange()`. When `true`, this instruction implies that extensions can change the shipping address.
      

```jsx
import {
  Banner,
  Button,
  useApplyShippingAddressChange,
  useInstructions,
  reactExtension,
} from '@shopify/ui-extensions-react/checkout';

export default reactExtension(
  'purchase.checkout.block.render',
  () => <Extension />,
);

function Extension() {
  const applyShippingAddressChange =
    useApplyShippingAddressChange();
  const instructions = useInstructions();

  if (
    instructions.delivery.canSelectCustomAddress
  ) {
    return (
      <Button
        onPress={() =>
          applyShippingAddressChange({
            type: 'updateShippingAddress',
            address: {
              zip: '90201',
            },
          })
        }
      >
        Change your postal code
      </Button>
    );
  } else {
    return (
      <Banner status="warning">
        Shipping address cannot be modified
      </Banner>
    );
  }
}

```

```js
import {
  extension,
  Banner,
  Button,
} from '@shopify/ui-extensions/checkout';

export default extension(
  'purchase.checkout.block.render',
  (root, api) => {
    if (
      api.instructions.current.delivery
        .canSelectCustomAddress
    ) {
      root.appendChild(
        root.createComponent(
          Button,
          {
            onPress: () =>
              api.applyShippingAddressChange({
                type: 'updateShippingAddress',
                address: {
                  zip: '90201',
                },
              }),
          },
          'Change your postal code',
        ),
      );
    } else {
      root.appendChild(
        root.createComponent(
          Banner,
          {},
          'Shipping address cannot be modified',
        ),
      );
    }
  },
);

```



      Check `instructions.discounts.canUpdateDiscountCodes` before calling `applyDiscountCodeChange()`.
      

```jsx
import {
  Banner,
  Button,
  useApplyDiscountCodeChange,
  useInstructions,
  reactExtension,
} from '@shopify/ui-extensions-react/checkout';

export default reactExtension(
  'purchase.checkout.block.render',
  () => <Extension />,
);

function Extension() {
  const applyDiscountCodeChange =
    useApplyDiscountCodeChange();
  const instructions = useInstructions();

  if (
    instructions.discounts.canUpdateDiscountCodes
  ) {
    return (
      <Button
        onPress={() =>
          applyDiscountCodeChange({
            type: 'addDiscountCode',
            code: 'FREE_SHIPPING',
          })
        }
      >
        Apply your loyalty discount
      </Button>
    );
  } else {
    return (
      <Banner status="warning">
        Loyalty discounts are unavailable
      </Banner>
    );
  }
}

```

```js
import {
  extension,
  Banner,
  Button,
} from '@shopify/ui-extensions/checkout';

export default extension(
  'purchase.checkout.block.render',
  (root, api) => {
    if (
      api.instructions.current.discounts
        .canUpdateDiscountCodes
    ) {
      root.appendChild(
        root.createComponent(
          Button,
          {
            onPress: () =>
              api.applyDiscountCodeChange({
                type: 'addDiscountCode',
                code: 'FREE_SHIPPING',
              }),
          },
          'Apply your loyalty discount',
        ),
      );
    } else {
      root.appendChild(
        root.createComponent(
          Banner,
          {},
          'Loyalty discounts are unavailable',
        ),
      );
    }
  },
);

```



      Check `instructions.lines.canAddCartLine` or `instructions.lines.canRemoveCartLine` or `instructions.lines.canUpdateCartLine` before calling `applyCartLinesChange()`.
      

```jsx
import {
  Banner,
  Button,
  useApplyCartLinesChange,
  useInstructions,
  reactExtension,
} from '@shopify/ui-extensions-react/checkout';

export default reactExtension(
  'purchase.checkout.block.render',
  () => <Extension />,
);

function Extension() {
  const applyCartLinesChange =
    useApplyCartLinesChange();
  const instructions = useInstructions();

  if (instructions.lines.canAddCartLine) {
    return (
      <Button
        onPress={() =>
          applyCartLinesChange({
            type: 'addCartLine',
            merchandiseId:
              'gid://shopify/product/1234',
            quantity: 1,
          })
        }
      >
        Add a free gift to your order
      </Button>
    );
  } else {
    return (
      <Banner status="warning">
        The products in your cart cannot be
        modified
      </Banner>
    );
  }
}

```

```js
import {
  extension,
  Banner,
  Button,
} from '@shopify/ui-extensions/checkout';

export default extension(
  'purchase.checkout.block.render',
  (root, api) => {
    if (
      api.instructions.current.lines
        .canAddCartLine
    ) {
      root.appendChild(
        root.createComponent(
          Button,
          {
            onPress: () =>
              api.applyCartLinesChange({
                type: 'addCartLine',
                merchandiseId:
                  'gid://shopify/product/1234',
                quantity: 1,
              }),
          },
          'Add a free gift to your order',
        ),
      );
    } else {
      root.appendChild(
        root.createComponent(
          Banner,
          {},
          'The products in your cart cannot be modified',
        ),
      );
    }
  },
);

```



      Check `instructions.metafields.canSetCartMetafields` or `instructions.metafields.canDeleteCartMetafields` before calling `applyMetafieldChange()` if you are working with cart metafields.
      

```jsx
import {
  Banner,
  Button,
  useApplyMetafieldChange,
  useInstructions,
  reactExtension,
} from '@shopify/ui-extensions-react/checkout';

export default reactExtension(
  'purchase.checkout.block.render',
  () => <Extension />,
);

function Extension() {
  const applyMetafieldChange =
    useApplyMetafieldChange();
  const instructions = useInstructions();

  if (
    instructions.metafields.canSetCartMetafields
  ) {
    return (
      <Button
        onPress={() =>
          applyMetafieldChange({
            type: 'updateCartMetafield',
            metafield: {
              namespace: 'loyalty',
              key: 'loyaltyPoints',
              value: '100',
              type: 'string',
            },
          })
        }
      >
        Apply 100 loyalty points
      </Button>
    );
  } else {
    return (
      <Banner status="warning">
        Loyalty points are unavailable
      </Banner>
    );
  }
}

```

```js
import {
  extension,
  Banner,
  Button,
} from '@shopify/ui-extensions/checkout';

export default extension(
  'purchase.checkout.block.render',
  (root, api) => {
    if (
      api.instructions.current.metafields
        .canSetCartMetafields
    ) {
      root.appendChild(
        root.createComponent(
          Button,
          {
            onPress: () =>
              api.applyMetafieldChange({
                type: 'updateCartMetafield',
                metafield: {
                  namespace: 'loyalty',
                  key: 'loyaltyPoints',
                  value: '100',
                  type: 'string',
                },
              }),
          },
          'Apply 100 loyalty points',
        ),
      );
    } else {
      root.appendChild(
        root.createComponent(
          Banner,
          {},
          'Loyalty points are unavailable',
        ),
      );
    }
  },
);

```



      Check `instructions.notes.canUpdateNote` before calling `applyNoteChange()`.
      

```jsx
import {
  Banner,
  Button,
  useApplyNoteChange,
  useInstructions,
  reactExtension,
} from '@shopify/ui-extensions-react/checkout';

export default reactExtension(
  'purchase.checkout.block.render',
  () => <Extension />,
);

function Extension() {
  const applyNoteChange = useApplyNoteChange();
  const instructions = useInstructions();

  if (instructions.notes.canUpdateNote) {
    return (
      <Button
        onPress={() =>
          applyNoteChange({
            type: 'updateNote',
            note: 'Please include a free gift.',
          })
        }
      >
        Include a free gift with your order
      </Button>
    );
  } else {
    return (
      <Banner status="warning">
        Free gifts cannot be added to this order
      </Banner>
    );
  }
}

```

```js
import {
  extension,
  Banner,
  Button,
} from '@shopify/ui-extensions/checkout';

export default extension(
  'purchase.checkout.block.render',
  (root, api) => {
    if (
      api.instructions.current.notes.canUpdateNote
    ) {
      root.appendChild(
        root.createComponent(
          Button,
          {
            onPress: () =>
              api.applyNoteChange({
                type: 'updateNote',
                note: 'Please include a free gift.',
              }),
          },
          'Include a free gift with your order',
        ),
      );
    } else {
      root.appendChild(
        root.createComponent(
          Banner,
          {},
          'Free gifts cannot be added to this order',
        ),
      );
    }
  },
);

```