JSFiddle - React, Tailwind, and code Playground

HTML

<!DOCTYPE html>
<html>
<head>
    <script>
        window.onload = function() {
            var canvas = document.getElementById('myCanvas');
            var ctx = canvas.getContext('2d');
            
            ctx.fillRect(10,50,100,200);
        };
    </script>
</head>
<body>
    <canvas id="myCanvas" width="400" height="600" />?
</body>
</html>