Dropzone images are not arriving on the server

I have a normal form and I inserted the drozpone inside it following some tips by the community. When I submit it, the dropzone images do not arrive at all on the server, $ _FILES is empty.

FORM HTML

   <form class="multi-page-form" method="post" id="form_publish" enctype="multipart/form-data">
   <div class="row">
      <!-- Dropzone -->
      <div class="dropzone dropzone-previews" id="my-awesome-dropzone"></div>
      <div class="col-lg-6 col-md-6">
         <div class="form-block">
            <label>Título do anúncio</label>
            <input class="border" type="text" name="title">
         </div>
      </div>
      <div class="col-lg-6 col-md-6">
         <div class="form-block">
            <label>Palavras-chave</label>
            <input type="text" placeholder="Insira suas palavras chaves" class="border" data-role="tagsinput" name="keywords" id="tagPlaces">
         </div>
      </div>
      <div class="center">
         <button type="button" id="btn-send-property" class="button button-icon large alt"><i class="fa fa-angle-right"></i> Enviar Imóvel</button>
      </div>
   </div>
</form>

JavaScript

    Dropzone.autoDiscover = false;
var myDropzone = new Dropzone('#my-awesome-dropzone', {
    url: 'User/publish',
    paramName: "files",
    autoDiscover: false,
    addRemoveLinks: true,
    maxFilesize: 3.0,
    maxFiles: 30,
    parallelUploads: 10000,
    uploadMultiple: true,
    autoProcessQueue: false
});

$("#btn-send-property").click(function () {
    myDropzone.processQueue();
    $("#form_publish").submit();
});

PHP

echo '<pre>';
    var_dump($_FILES);
    echo '</pre>';
    die();