As of API version
2023-04, you can retrieve a subset of fulfillment orders which are assigned to locations owned by the app performing the request but have not been requested for fulfillment so far.
assignment_status query parameter in the [/assignedfulfillmentorders.json]((https://shopify.dev/docs/api/admin-rest/latest/resources/assignedfulfillmentorder#get-assigned-fulfillment-orders) endpoint can now accept a value of
fulfillment_unsubmitted for filtering in addition to the existing
cancellation_requested filter values.
Learn more about retrieving assigned fulfillment orders as a fulfillment service on shopify.dev.