<!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>