index.html

<!doctype html>
<html lang="en">
  <head>
    <meta charset="utf-8">
    <title>GrapesJS Plugin Forms</title>
    <link rel="stylesheet" href="https://unpkg.com/grapesjs/dist/css/grapes.min.css">
    <script src="https://unpkg.com/grapesjs"></script>
    <style>
      body, html{ height: 100%; margin: 0;}

      .gjs-block-svg {
          width: 61%;
      }

      .gjs-block-svg-path {
        fill: white;
      }
    </style>
  </head>
  <body>

    <div id="gjs" style="height:0px; overflow:hidden">
      <form action="index.html" method="post" style="padding: 50px;">
        <input type="hidden" name="hidden-input" value="someval">
        <div class="row">
          <label>Name</label>
          <input type="text" name="text-input" value="">
        </div>
        <div class="row">
          <label>Messagge</label>
          <textarea name="textarea-input"></textarea>
        </div>
        <div class="row">
          <label>Options</label>
          <select name="select-input">
            <option value="">- Select -</option>
            <option value="1">Value 1</option>
            <option value="2">Value 2</option>
            <option value="3">Value 3</option>
          </select>
        </div>
        <div class="row">
          <input type="checkbox" name="checkbox-input" value="1"> Test
        </div>
        <div class="row">
          <input type="radio" name="radio-input" value="1"> 1
          <input type="radio" name="radio-input" value="2"> 2
          <input type="radio" name="radio-input" value="3"> 3
        </div>
        <button type="button" name="button-name">Send</button>
      </form>
      <style>
      </style>
    </div>


    <script type="text/javascript">
      window.onload = () => {
        window.editor = grapesjs.init({
          height: '100%',
          noticeOnUnload: false,
          storageManager: false,
          container : '#gjs',
          fromElement: true,

          plugins: ['grapesjs-plugin-forms'],
          pluginsOpts: {
            'grapesjs-plugin-forms': {}
          }
        });
      };
    </script>
  </body>
</html>