How do I resolve a FulfillmentRequest API error in my custom app?

Topic summary

Custom app using Shopify’s FulfillmentRequest API: orders list successfully, but changing an order’s status on a “confirm” action fails. The request targets Admin REST 2023-10 at /admin/api/2023-10/fulfillment_orders/1046000829 with a fulfillment_request.json payload.

Error encountered: “The fulfil lment order’s assigned fulfillment service must be of api type”. This indicates the fulfillment order is assigned to a non-API fulfillment service, which blocks FulfillmentRequest operations.

Resources referenced: Shopify documentation for FulfillmentRequest (Admin REST 2023-10) is linked. A screenshot attachment shows the error response.

Current state: the author is seeking assistance and a resolution; no fixes, workarounds, or confirmations from others yet. The issue remains open with the key question of how to meet the API-type fulfillment service requirement or otherwise change the order status via the intended endpoint.

Summarized with AI on January 15. AI used: gpt-5.

Dear all: What’s up everyone?
When utilizing the FulfillmentRequest APIs, I have a problem.
I have developed a customized app where I want to list the orders generated for the products within the app. All orders are successfully listed.

However, I want to change the order’s status once the confirm button has been clicked.

I’m using the file fulfillment_request.json at /admin/api/2023-10/fulfillment_orders/1046000829.

, and I got

“errors”: [

“The fulfillment order’s assigned fulfillment service must be of api type”

]

}

This error.If someone can assist me in resolving this problem, please let me know.
Here is the documentation: https://shopify.dev/docs/api/admin-rest/2023-10/resources/fulfillmentrequest
Greetings and many thanks to all.