Maarten van Grootel commented on Fulfillment API - Create a fulfillment for all lines

That last URL is incorrect. That should be https://xxxxx:yyyy@nooodle.myshopify.com/admin/orders/231298777/fulfillments.json

#1004 is the Order number or name, _not_ the Order ID. 

Could you try and see if using the right id solves your problem?