Remove order_reference apparently

source/static/payshipment.php

@@ -70,7 +70,7 @@ try {
                             "quantity" => 1,
                             "unit_cost" => $price * 100,
                             "unit_of_measure" => "each",
-                            "product_code" => "$shipment->tracking_code",
+                            "product_code" => "CRTFIEDMAIL",
                             "tax" => [
                                 "total_tax_amount" => 0
                             ],
@@ -81,9 +81,6 @@ try {
                             ]
                         ]
                     ]
-                ],
-                "payment_details" => [
-                    "order_reference" => "$shipment->tracking_code"
                 ]
             ]);
         } catch (Exception $exx) {