YouTube autoplay not working with JQuery

The YouTube video is supposed to play automatically when you press the blue “play” button. It was working, but seemed to stop overnight. Not sure where it’s gone wrong.

See: The Amazon Adventure - Episode 1 | Watch | Fantail Studios

$('.button-large-1').on('click', function(ev) {
  $(".embedly-embed")[0].src += "&autoplay=1";
$('.button-close-1').on('click', function(ev) {
  var videoURL = $('.embedly-embed').prop('src');
  videoURL = videoURL.replace("&autoplay=1", "");

Any help you can provide would be greatly appreciated, though I ask that if the JQuery needs updating, can you please provide the full corrected code so I can follow. Thank you.