module-examples/dynamic-module-imports/index.html

<!DOCTYPE html>
<html lang="en-US">
  <head>
    <meta charset="utf-8">
    <title>Dynamic module class example</title>
    <style>
      canvas {
        border: 1px solid black;
        margin-top: 10px;
      }
    </style>
    <script type="module" src="main.js"></script>
  </head>
  <body>
    <button class="circle">Circle</button>
    <button class="square">Square</button>
    <button class="triangle">Triangle</button>

  </body>
</html>