Failed to load resource: the server responded with a status of 404 (Not Found) mistakes shows himself in console for Lighbtox.js. I downloaded the file and put into the my js file, I put the url path corrcetly to the bottom of my project after bootstrap and jquery js files.
I downloaded the file from original place.
I created a minimal working example as follows. It does work with the latest jquery. Make sure jquery script tag is before the lightbox script tag.
my index.html
<html>
<head>
<script src="js/jquery-3.4.1.min.js"></script>
<link href="css/lightbox.min.css" rel="stylesheet" />
</head>
<body>
<a href="images/image-1.png" data-lightbox="image-1" data-title="TESTING">Image #1</a>
<script src="js/lightbox.min.js"></script>
</body>
</html>
File structure
And the result