ok

resources/views/pay/middleware.blade.php

@@ -7,7 +7,7 @@
     <meta http-equiv="X-UA-Compatible" content="ie=edge">
 </head>
 <script>
-        window.location.href = {{$mweb_url}};
+    window.location.href = "{{$mweb_url}}";
 </script>
 
 </html>