Programmatically releasing and order to a fulfilment service

[Geordie_ca]

Hi,

I'm trying to convert our integration to the new fulfilment service model.  I have been able to figure out how to automate all the steps in the fulfilment process, except the step where the user clicks the 'Request Fulfilment' button.

I have tried to use the 'fulfillmentOrderSubmitFulfillmentRequest' API as the description fits what I want to do.

'Sends a fulfillment request to the fulfillment service of a fulfillment order.'

But I get a 'Fulfillment order does not exist' error. when I try to pass the order ID as 

"gid://shopify/FulfillmentOrder/4574488985684" or an 'Invalid ID' if I use 

"gid://shopify/Order/4574488985684".

I also looked at the order APIs and could not find an API that looked like it would initiate the fulfilment service process.

Any help would be much appreciated.

[Geordie_ca]

I think I have this figured out.  If I use the 'Get Order By ID' API , the system can return a fulfilment ID, that I can then use to call the fulfilment API's in the fulfilment process. 

In fact I just checked and using this API, I can by pass the whole callback and accept fulfillment process steps and go straight to 'FulfilmentCreateV2' API and mark the order as Fulfilled and collect payment.