my html form looks like this

<form id="upload-form" class="dropzone">
  <!-- this is were the previews should be shown. -->
  <div class="previews"></div>
  
  <!-- Now setup your input fields -->
  <input type="file" name="file">
  <button type="submit">Submit data and files!</button>
</form>

and the script configuration

Dropzone.options.uploadForm = { // The camelized version of the ID of the form element
  // The configuration we've talked about above
  autoProcessQueue: false,
  uploadMultiple: true,
  parallelUploads: 100,
  maxFiles: 100,
  // The setting up of the dropzone
  init: function() {
    var myDropzone = this;
    // First change the button to actually tell Dropzone to process the queue.
    this.element.querySelector("button[type=submit]").addEventListener("click", function(e) {
      // Make sure that the form isn't actually being sent.
      e.preventDefault();
      e.stopPropagation();
      myDropzone.processQueue();
    });
    // Listen to the sendingmultiple event. In this case, it's the sendingmultiple event instead
    // of the sending event because uploadMultiple is set to true.
    this.on("sendingmultiple", function() {
      // Gets triggered when the form is actually being sent.
      // Hide the success button or the complete form.
    });
    this.on("successmultiple", function(files, response) {
      // Gets triggered when the files have successfully been sent.
      // Redirect user or notify of success.
    });
    this.on("errormultiple", function(files, response) {
      // Gets triggered when there was an error sending the files.
      // Maybe show form again, and notify user of error
    });
  }
}

I just serach the internet much and as I read the doc and other examples it should work but, it doesn't.