subline horizontal gallery

Hi,
I have inserted the code in the child theme from the thread #1016668. It does not work, except in the customizer. There can I see the captions. Can you help me?
What is wrong?
Or is it possible to realize that with CSS like this: content: attr(title); ?

<?php

/*
* Add your own functions here. You can also copy some of the theme functions into this file.
* WordPress will use those functions instead of the original functions then.
*/

function horizontal_gallery_subline(){
?>
<script>
(function($){
$(window).load(function() {
$(‘.av-horizontal-gallery-link’).css(‘bottom’, ’30px’);
$(‘.av-horizontal-gallery-img’).each(function(){
var imgTitle = $(this).attr(‘title’);
$(this).after(‘<p class=”text-under-image”>’ + imgTitle + ‘</p>’);
$(this).css({
‘padding-bottom’ : ’20px’,
‘background-color’ : ‘transparent’,
});
$(‘.text-under-image’).css({
“text-align”: “center”,
“margin”: “-20px 0”,
“color”: “#ffffff”,
});
});
});
})(jQuery);
</script>
<?php
}
add_action(‘wp_footer’, ‘horizontal_gallery_subline’);