Easy FancyBox Button helper

hello,

How to add Button helper to Easy FancyBox Plugin.

i have add to footer but my site not show Button helper

<script type="text/javascript">
jQuery(document).on('ready post-load', function() {
$('.fancybox').fancybox({
 openEffect  : 'none',
 closeEffect : 'none',
 prevEffect : 'none',
 nextEffect : 'none',
 closeBtn  : false,
 arrows    : false,
 nextClick : true,
 helpers : {
  title : {
   type : 'inside'
  },
  buttons : {},
  thumbs : {
   width : 50,
   height : 50
  }
 },
 afterLoad : function() {
  this.title = 'Image ' + (this.index + 1) + ' of ' + this.group.length + (this.title ? ' - ' + this.title : '');
 }
});
} );
</script>

Any for support. Thanks

https://wordpress.org/plugins/easy-fancybox/