Fulfillment POST returns "Fulfillment order line item does not exist." - But it does?

[Mowtine]

I am trying to fulfil an order with the API. 

I get the fulfillment_orders for the order:

{
"fulfillment_orders": [
        {
"id": 5162433085613,
"shop_id": ***,
"order_id": 4183684907181,
            ...
"supported_actions": [
"create_fulfillment",
"hold"
            ],
"destination": null,
"line_items": [
                {
"id": 10909262577837,
"shop_id": ***,
"fulfillment_order_id": 5162433085613,
"quantity": 1,
"line_item_id": 10763713675437,
"inventory_item_id": 43141097849005,
"fulfillable_quantity": 1,
"variant_id": 41044827701421
                }
            ],
"fulfill_at": null,
            ...
        }
    ]
}

and I use the id for the fulfilment and line_item_id for id for line item:

{"fulfillment":{"message":"MSG","notify_customer":true,
"tracking_info": {"number": 1562678,"url": "https://www.my-shipping-company.com","company": "my-shipping-company"},
    "line_items_by_fulfillment_order":[
{"fulfillment_order_id":5162433085613,
"fulfillment_order_line_items":[
    {"id":10763713675437,
    "quantity":1}
]}]}}​

but when posting that I get: 

"Fulfillment order line item does not exist."

What am I doing wrong here?

Thanks. 

[Mowtine · Accepted solution]

Found the problem. The tutorial at: https://shopify.dev/apps/fulfillment/order-management-apps is INCORRECT.

You can't use: https://{shop}.myshopify.com/admin/api/2021-10/fulfillments.json

You must use: https://{shop}.myshopify.com/admin/api/2021-10/orders/<number>/fulfillments.json

to fulfil an order.