Shopify Fulfillment Api returns : Request failed with HTTP Code 404

Payments + Shipping & Fulfilment
1

Hello,
I’m trying to post to the Fulfillment API to fulfill line items on an order using following code:

$config = array(
‘ShopUrl’ => ‘XXXX.myshopify.com’,
‘AccessToken’ => ‘myAccessToken’
);

$shopify = new ShopifySDK($config);

$orderID = 111111111111;
$line_items = array();
$line_items = array(“id” => 22222222222222);
$data = array(
“location_id” => “33333333”,
“tracking_number” => null,
“status” => “open”,
“line_items” => $line_items
);

$fulfillmentData = $shopify->Order($orderID)->Fulfillment->post($data);

However I’m getting response “Request failed with HTTP Code 404” back from the API. I’ve verified OrderID, LocationId & LineItemId they are correct (using dummy data in this post)
I’ve tried it with tracking_number: null, and also with no tracking number at all, but it’s always the same: 404.
It was working up until a few days ago.

I can’t figure out why it stopped working. I hope someone can help.

Thanks a lot in advance!