Would you like a video to begin playing as soon as a viewer clicks on a guide homepage or other page within your guide? Autoplay may be attention getting, but it can also be annoying to viewers, so it should be used sparingly. If you believe a viewer will be returning to this page over and over, they will likely become more annoyed with it over time, so you may only want to use autoplay on pages you think have information that will only be need once. Also consider whether you want the sound to play or for the video to be mute. The movement of the video will get attention in and of itself, and it gives the option to the viewer of whether to turn on the sound. 

First, find the embed URL for a YouTube video by selecting Share. Copy the URL. 

If the embed URL ends with a question mark (?), add the following code to the end of the URL
For autoplay only: autoplay=1
For autoplay + mute: autoplay=1&mute=1

If the embed URL does not end with a question mark (?), add the following code to the end of the URL
For autoplay only: ?autoplay=1
For autoplay + mute: ?autoplay=1&mute=1

Example

<div class="embed-responsive embed-responsive-16by9">
<iframe allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture" allowfullscreen="" class="embed-responsive-item" frameborder="0" src="https://www.youtube.com/embed/BYgPi5SFudg?autoplay=1&mute=1" title="YouTube video player"></iframe>
</div>