Форма не отправляет файлы через ajax

$('#contact-form').submit(function(e) {
  e.preventDefault();
  const form = $(this),


    formData = $(form).serialize(),
    url = '/obrabotchik-formy-vakansii.php';


  $.ajax({
    type: 'POST',
    url: url,
    data: formData,
    cache: false,
    contentType: false,
    processData: false,
  })
});

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<form id="contact-form">
  <div class="controls">
    <div class="form-group">
      <input id="form_name" type="text" name="name" placeholder="Как вас зовут?">
    </div>
    <div class="form-group">
      <input class="mask-phone" id="form_email" type="text" name="phone" placeholder="Телефон">
    </div>
    <div class="form-group">
      <input id="form_email" type="text" name="email" placeholder="Email">
    </div>
    <div class="form-group">
      <textarea id="form_message" name="message" placeholder="Задайте вопрос" rows="4"></textarea>
    </div>
    <input id="resume" name="resum" style="" type="file">
    <input type="hidden" value="v8lcf44j3u" name="token">
    <div class="form-result"></div>
    <button type="submit" class="btn-curve btn-blc"><span>Отправить</span></button>
  </div>
</form>