Anyone tried to use the

PUT .../record/v1/itemFulfillment/{:id}

endpoint before in the REST API to create item fulfillment? Our client is using a system that doesn't provide a way to use the

POST .../record/v1/salesOrder/{:id}/!transform/item...

endpoint... so we have to use PUT, but it always gives this error.

Error while accessing a resource. You have attempted an invalid sublist or line item operation. You are either trying to access a field on a non-existent line or you are trying to add or remove lines from a static sublist.