I'm trying the following code on WordPress post page:
<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);
    // 3. This function creates an <iframe> (and YouTube player)
    //    after the API code downloads.
    var player;
    function onYouTubeIframeAPIReady() {
        player = new YT.Player('player', {
            height: '390',
            width: '640',
            videoId: 'M7lc1UVf-VE',
            playerVars: { 'autoplay': 1, 'controls': 0 },
            events: {
                'onReady': onPlayerReady,
                'onStateChange': onPlayerStateChange
            }
        });
    }
    // 4. The API will call this function when the video player is ready.
    function onPlayerReady(event) {
        event.target.playVideo();
    }
    // 5. The API calls this function when the player's state changes.
    //    The function indicates that when playing a video (state=1),
    //    the player should play for six seconds and then stop.
    var done = false;
    function onPlayerStateChange(event) {
        if (event.data == YT.PlayerState.PLAYING && !done) {
            setTimeout(stopVideo, 6000);
            done = true;
        }
    }
    function playVideo() {
        player.playVideo();
    }
    function pauseVideo() {
        player.pauseVideo();
    }
    function stopVideo() {
        player.stopVideo();
    }
    function loadVideoById(val) {
        player.loadVideoById(val, 0, "large");
    }
</script>
However, nothing was displayed.
 
     
     
     
    