In version 1.1.23 the Shopify version was updated from 2022-01 to 2022-07. There are some breaking changes between these versions. This now results in 404 NOT found: ` $client->Order($order->Order_ID)->Fulfillment->post($body);` ``` 200: admin/api/2022-01/orders/{order_id}/fulfillments.json 404: admin/api/2022-07/orders/{order_id}/fulfillments.json ``` Instead now you will have to send to a different location, with an entirely different payload. admin/api/2022-07/fulfillments.json I believe what would be needed is ` $client->Fulfillments` And remove ` $client->Order($order->Order_ID)->Fulfillment` For others with the same problem, I have fixed my version to 1.1.22