first upload all files

Modules/Payment/GatewayResponse.php

@@ -0,0 +1,31 @@
+<?php
+
+namespace Modules\Payment;
+
+use JsonSerializable;
+
+abstract class GatewayResponse implements JsonSerializable
+{
+    abstract public function getOrderId();
+
+    public function toArray()
+    {
+        $data = ['orderId' => $this->getOrderId()];
+
+        if ($this instanceof ShouldRedirect) {
+            $data['redirectUrl'] = $this->getRedirectUrl();
+        }
+
+        return $data;
+    }
+
+    public function jsonSerialize()
+    {
+        return $this->toArray();
+    }
+
+    public function __toString()
+    {
+        return json_encode($this->jsonSerialize());
+    }
+}