Mark Orders as fulfilled Automatically - Old API depreciated

Hi, we have been using a Rest API call to flag staff Shopify orders as fulfilled.

It appears that the method we were using has been depreciated and just does nothing.

The current way of doing this was to run the following

curl -s -d ‘{“fulfillment”:{“location_id”:XXXXXXXXXX,“tracking_number”:null,“tracking_urls”:[],“notify_customer”:true}}’ -X POST “https://<accesstoken>@sippify.myshopify.com/admin/api/2022-04/orders/5254020563200/fulfillments.json” -H “Content-Type: application/json”

Looking at the docs the new way is to use FulfillmentOrder as opposed to fulfilments.

Can someone please suggest how to do this the new way using the REST API.