1 Method.
Change autoplay policy in chrome://flags/#autoplay-policy to "No user gesture is required"
https://developers.google.com/web/updates/2017/09/autoplay-policy-changes
2 Method.
Use script
<div id="player"></div>
<script>
// 2. This code loads the IFrame Player API code asynchronously.
var tag = document.createElement('script');
tag.src = "https://www.youtube.com/iframe_api";
var firstScriptTag = document.getElementsByTagName('script')[0];
firstScriptTag.parentNode.insertBefore(tag, firstScriptTag);
function onYouTubeIframeAPIReady() {
var player;
player = new YT.Player('player', {
videoId: '439frli5VbM', // YouTube Video ID
width: 560, // Player width (in px)
height: 316, // Player height (in px)
playerVars: {
autoplay: 1, // Auto-play the video on load
controls: 1, // Show pause/play buttons in player
showinfo: 0, // Hide the video title
modestbranding: 1, // Hide the Youtube Logo
loop: 1, // Run the video in a loop
fs: 0, // Hide the full screen button
cc_load_policy: 0, // Hide closed captions
iv_load_policy: 3, // Hide the Video Annotations
autohide: 0 // Hide video controls when playing
},
events: {
onReady: function(e) {
e.target.mute();
}
}
});
}
</script>