Getting blank array as response for fulfillment orders API.

[vladosky]

I want to update the tracking information for an order using fulfillments API. 
But we don't have fulfillment_order_id. To get fulfillment_order_id we use this API

/admin/api/2022-10/orders/{order_id}/fulfillment_orders.json

 but we are getting a blank array as the response.
Can anyone help me out, how I create a fulfillment order? 
We use private app credentials for all API calls.

[XPStudio]

Same problem here. Looks like problem with order_it

[XPStudio]

Fixed it by adding:

$session = curl_init();
curl_setopt($session, CURLOPT_URL, $url);
curl_setopt($session, CURLOPT_HTTPGET, 1);
curl_setopt($session, CURLOPT_HEADER, false);
curl_setopt($session, CURLOPT_HTTPHEADER, array('Accept: application/xml', 'Content-Type: application/xml'));
curl_setopt($session, CURLOPT_RETURNTRANSFER, true);
curl_setopt($session, CURLOPT_SSL_VERIFYHOST,0);
curl_setopt($session, CURLOPT_SSL_VERIFYPEER,0);
$response = curl_exec($session);
curl_close($session);