Как отключить воспроизведение видео?

$('.modal').modal();

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<link href="https://cdnjs.cloudflare.com/ajax/libs/materialize/1.0.0/css/materialize.min.css" rel="stylesheet"/>
<script src="https://cdnjs.cloudflare.com/ajax/libs/materialize/1.0.0/js/materialize.min.js"></script>
  <a class="waves-effect waves-light btn modal-trigger" href="#video1">Видео</a>
    <!-- Modal Structure -->
  <div id="video1" class="modal">
    <div class="modal-content">
<iframe width="560" height="315" src="https://www.youtube.com/embed/QLQ3sLSrfwI" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share" allowfullscreen></iframe>
    </div>
  </div>