When looking at the jsfiddle you provided based on your implementation, it seems that the issue lies in how you are referencing the JS file. It is not possible to directly link to script files on github because they do not serve script files with the appropriate content type (see here for more information). The gist of it is that Github does not want to be used as a CDN.
After making adjustments to the fiddle, it appears that the plugin is now functioning correctly.
Here is a code snippet that mirrors the code from the fiddle:
$('#easyPaginate').easyPaginate({
paginateElement: 'img',
elementsPerPage: 3,
effect: 'climb'
});
body {
font-family: Arial, sans-serif;
text-align: center;
max-width: 1170px;
margin: 3rem auto;
background-color: #101010;
color: #fff;
}
/* Cosmetic only */
#easyPaginate {display: grid;
grid-template-columns: repeat(3, 1fr);
grid-gap: 20px;max-width: 1000px;
height: auto
margin: 0 auto;}
#easyPaginate img {width: 100%;
height: 150px;
padding: 5px;
border: none;
background: transparent;
object-fit: cover;
position: relative;
}
@media only screen and (max-width: 600px) {
.easyPaginate {
grid-template-columns: repeat(3, 1fr);
}
}
.easyPaginate img:hover {
z-index: 9;
transform: scale(1.3);
transition: transform ease 0.5s;
}
.easyPaginateNav a {padding:5px;}
.easyPaginateNav a.current {font-weight:bold;text-decoration:underline;}
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<script src="https://st3ph.github.io/jquery.easyPaginate/js/jquery.easyPaginate.js"></script>
<div id="easyPaginate" class="easyPaginateList">
<img src="https://picsum.photos/500/500?random&img=" />
<img src="https://picsum.photos/500/500?random&img=" />
<img src="https://picsum.photos/500/500?random&img=" />
<img src="https://picsum.photos/500/500?random&img=" />
<img src="https://picsum.photos/500/500?random&img=" />
<img src="https://picsum.photos/500/500?random&img=" />
<img src="https://picsum.photos/500/500?random&img=" />
<img src="https://picsum.photos/500/500?random&img=" />
<img src="https://picsum.photos/500/500?random&img=" />
<img src="https://picsum.photos/500/500?random&img=" />
<img src="https://picsum.photos/500/500?random&img=" />
<img src="https://picsum.photos/500/500?random&img=" />
</div>