Adding caption to each slide in horizontal gallery

you can try this in your child-theme functions.php:

function horizontal_gallery_subline(){
?>
<script>
(function($){
    $(window).load(function() {
	   $('.av-horizontal-gallery-link').each(function(){
            var linkTitle = $(this).attr('title');
            $(this).closest('.av-horizontal-gallery').css("overflow", "visible" )           
            $(this).before('<p class="text-under-image">' + linkTitle + '</p>');
            $('.text-under-image').css({
            	"text-align": "center",
            	"margin": "0.2em 0",
            });
        });
    });
})(jQuery);
</script>
<?php
}
add_action('wp_footer', 'horizontal_gallery_subline');

see here: https://webers-testseite.de/horizontal-gallery/

btw: this will work with active image style enlarge too

by the way – for screens under 768px:

@media only screen and (max-width: 767px){
	.text-under-image {
	    position: absolute !important;
	    background-color: #fff;
	    bottom: 0;
	    left: 50%;
	    transform: translateX(-50%);
	    padding: 0 30px;
	    margin: 0 !important;
	    text-shadow: 1px 1px 2px #aaa;
	    border-radius: 8px 8px 0 0;
	}
}

see example page: https://webers-testseite.de/horizontal-gallery/#next

well you are talking about Caption – the Caption on horizontal Gallery is this field under the image:
(see the empty field on the left – and what happend then to the frontend.
click to enlarge:

or on media library you can see where the caption is.
If yo like to have a different field – better tell me:

so remove the code
and see if your nested construct will work without code anyway.
Because you have horizontal gallery in tab-section ? isn’t so – so first try your construction
If it works – then insert this instead:

• This reply was modified 6 years, 2 months ago by Guenni007.

Please remove the code i gave you – then i can better test a different one on web-developer tools:

i see on my page that it is working now with that nested construct:
https://webers-testseite.de/horizontal-gallery/

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": "#000",
            });
        });
    });
})(jQuery);
</script>
<?php
}
add_action('wp_footer', 'horizontal_gallery_subline');

• This reply was modified 6 years, 2 months ago by Guenni007.

So – not for that
And Yes – it is always better to have a live link.
Your Caption talking let me come to a solution which your source code does not have. – You see on the images where the caption is on Galleries.