how to auto play iframe code example
Example 1: iframe autoplay
<!--
first add ?autoplay=1 to your video url
then add allow='autoplay' attribute to your iframe element
-->
<iframe src="https://www.youtube.com/embed/dQw4w9WgXcQ?autoplay=1" allow='autoplay'></iframe>
Example 2: Iframe video autoplay
<iframe src="//www.youtube.com/embed/{{YOUTUBE-ID}}?autoplay=1&mute=1" name="youtube embed" allow="autoplay; encrypted-media" allowfullscreen></iframe>