#1. First, you need to enable Gallery Slideshow Arrows

#2. Next, use this code to Code Injection – Footer or Page Header Code Injection
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.7.0/jquery.min.js"></script>
<script>
jQuery(document).ready(function($) {
function run() {
if ($(window).width() < 991) {
setInterval(function(){
$('.gallery-slideshow-control-btn[data-next], .gallery-fullscreen-slideshow-control-btn[data-next]').click()
},3000);
}
}
run();
window.addEventListener('resize', run)
});
</script>
