fix payload

app/code/IpSupply/SyncOrder/Sync/Index.php

@@ -50,11 +50,8 @@ final class Index
             foreach ($order->getAllVisibleItems() as $item) {
                 $payload['details'][] = (new Detail($item))->jsonSerialize();
             }
-
             $this->_client()->post($this->_config['url'], [
-                'body' => [
-                    "magento_2_" . time() => $payload
-                ]
+                'json' => $payload
             ]);
 
             return json_encode($payload);