Copy-paste the following <script> near the end of your pages under JS Implementing Plugins to enable it.
<script src="../node_modules/fslightbox/index.js"></script>
<div class="row">
<div class="col-sm-4 mb-3 mb-sm-0">
<!-- media viewer -->
<a href="../../assets/img/login-banner-02.jpg" data-fslightbox="gallery">
<img class="img-fluid" src="../../assets/img/login-banner-05.jpg" alt="Image Description">
</a>
<!-- end media viewer -->
</div>
<!-- end col -->
<div class="col-sm-4 mb-3 mb-sm-0">
<!-- media viewer -->
<a href="../../assets/img/login-banner-04.jpg" data-fslightbox="gallery">
<img class="img-fluid" src="../../assets/img/login-banner-04.jpg" alt="Image Description">
</a>
<!-- end media viewer -->
</div>
<!-- end col -->
<div class="col-sm-4">
<!-- media viewer -->
<a href="../../assets/img/login-banner-03.jpg" data-fslightbox="gallery">
<img class="img-fluid" src="../../assets/img/login-banner-03.jpg" alt="Image Description">
</a>
<!-- end media viewer -->
</div>
<!-- end col -->
</div>
<div class="row">
<div class="col-sm-4 mb-3 mb-sm-0">
<a data-fslightbox="html5-video" data-video-poster="../../assets/img/big-bunny.png"
href="http://commondatastorage.googleapis.com/gtv-videos-bucket/sample/BigBuckBunny.mp4">
<img class="img-fluid" src="../../assets/img/big-bunny.png" alt="Image Description">
</a>
</div>
</div>
<div class="row">
<div class="col-sm-4 mb-3 mb-sm-0">
<a data-fslightbox="youtube-video" data-video-poster="../../assets/img/big-bunny.png"
href="https://www.youtube.com/watch?v=YE7VzlLtp-4">
<img class="img-fluid" src="../../assets/img/big-bunny.png" alt="Image Description">
</a>
</div>
</div>