<!DOCTYPE html>


<head>

  <meta name="viewport" content="width=device-width, initial-scale=1"> <!-- Ensures optimal rendering on mobile devices. -->

  <meta http-equiv="X-UA-Compatible" content="IE=edge" /> <!-- Optimal Internet Explorer compatibility -->

</head>


<body>

  <script

    src="https://www.paypal.com/sdk/js?client-id=YOUR_CLIENT_ID"> // Required. Replace YOUR_CLIENT_ID with your sandbox client ID.

  </script>

</body>