On my Prestashop I use YouTube videos in some product tabs. Here is an exemple :

<ul id="tabvideos" class="video_cols_6">
 <li id="thumb_video_118" class="video_link">
   <a id="video_link_1" class="videocenter" href="https://www.youtube-      nocookie.com/embed/ehzbdk" title="Vidéo: e" data-video-id="TLHyVnOzs10" data-video-player="youtube" data-video-title=""><img class="img-responsive" src="https://i.ytimg.com/vi/TLHyVedfdsdsdnOzs10/hqdefault.jpg" alt="e vidéo" title="e vidéo">
   </a>
 </li>
</ul>

We use a module and autoplay should be activated. It seems that a previous developer has been integrating some script somewhere so cancel this.

How to make all the YT videos on the website in autoplay?