index.html

<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <link rel="stylesheet" href="./index.css" />
    <title>Popup</title>
    <script type="module" src="./index.js"></script>
  </head>
  <body>
    <h1>Works Locally</h1>
    <button id="isenableBtn"></button>
    <label>From Webm to mp4</label>
    <form id="conversionForm">
      <div class="form-group">
        <label for="webpConvert">WebP to:</label>
        <select name="webpConvert" id="webpConvert">
          <option value="image/png">PNG</option>
          <option value="image/jpeg">JPEG</option>
        </select>
      </div>

      <input type="submit" value="Save" />
    </form>
  </body>
</html>