Fulfillment Order API

We call Completed Fulfillment interface,but we still got error as below. Please support on this issues. Thanks.

API link: https://shopify.dev/api/admin-rest/2021-10/resources/fulfillment#post-orders-order-id-fulfillments-fulfillment-id-complete

Fulfillment - Shopify Manage the fulfillment of an order’s line items. Create a fulfillment for each shipment, provide tracking information, and notify the customer that their items have shipped.

Body: {“complete”:“”}
Response: {“errors”:“An error occurred, please try again”}

Body: {}
Response: {“errors”:“An error occurred, please try again”}

You are going to have to provide more information if you want help. For example what does the endpoint look like. I don’t see anything where you it says you can send either an empty body in the post or a post with a body of “completed”

Cheers,

Gary