Add YouTube support to MetaSlider with Easy Fancybox

add-easy-fancybox-videos-metaslider.php

<?php
// Requires MS Lightbox
add_filter('metaslider_lightbox_supported_plugins', function ($attributes) {
    return [
        'Easy FancyBox' => [
            'location' => 'easy-fancybox/easy-fancybox.php',
            'settings_url' => 'options-media.php',
            'rel' => 'lightbox',
        ]
    ];
});
// Make sure the YouTube option is set from the Easy Fancybox settings page
// requires MS pro
add_filter('easy_fancybox_inline_script', function ($js) {
    return "
        window.jQuery('.ms-youtube').each(function(i, video) {
            var msytid = window.jQuery(video).find('.youtube').attr('data-id');
            if (msytid) {
                var galleryId = window.jQuery(video).closest('.metaslider').find('a[rel]').attr('rel');
                window.jQuery(video).wrapInner('<a rel=\''+galleryId+'\' href=\'https://youtu.be/'+msytid+'?hd=1&fs=1&autoplay=1\'>');
            }
        });
        $js";
}, 10, 2);