if(has_post_thumbnail()){
	$thumbnail_url = get_the_post_thumbnail_url(null, "large");

	//echo '<a href="'.$thumbnail1	a.'" data-featherlight="myimage.png">';

	printf('<a href="%s" data-featherlight="image">', $thumbnail_url);
	the_post_thumbnail( "large", array("class" => "img-fluid") );
	echo '</a>';
}