Untitled

<!DOCTYPE html>
<html lang="en" dir="ltr">
  <head>
    <meta charset="utf-8">
    <title></title>
  </head>
  <body>

            <form>
    <div>
    <p>
          <label>
            <input name="item" id="Agree" type="checkbox" class="red"/>
            <span>Agree</span>

          </label>
        </p>
        </div>

            <div class="input-field col s12">

            <button class="btn waves-effect waves-light" type="submit" name="action" id="btn">Generate
        <i class="material-icons right">send</i>
      </button>

        </div>
        </form>

       <script>

                var agreeValue = document.getElementById("Agree")


                document.getElementById("btn").addEventListener("click", addRecord);

                function addRecord() {
                var data = {
                agreeValue               : Agree.value
                };


                google.script.run.appendData(data);
                }


    </script>

  </body>
</html>