The identifier for the metafield linked to this option.
This API is currently in early access. See [Metafield-linked product options](https://shopify.dev/docs/api/admin/migrate/new-product-model/metafield-linked) for more details.
Access Scopes
`read_products` access scope.
Fields
key:
String -
Key of the metafield the option is linked to.
namespace:
String -
Namespace of the metafield the option is linked to.