Adding a class to each anchor tag

First off, I just want to say this is an awesome plugin!
It’s one of the best I have found for galleries. It’s more attractive than many of the paid plugins with the same purpose that I have access to.

I know this is asking for extra help, but I would really appreciate some insight into the issue I’m having.

I would like to add a class to each image so I can use a lightbox that is built into the theme I’m using. (The lightbox requires that each image has the class in the anchor tag) It would be awesome if there was a shortcode for this function like there is a shortcode to put a class on the gallery container.

Since there is not, I tried to do it myself with some Jquery, but after trying to implement a solution myself for a few hours… it has become clear that I’m not super talented with php and Jquery.

I put the following in my functions.php

<?php 

function add_my_script() {
    wp_enqueue_script(
      'lightbox_bridge', get_stylesheet_directory_uri() . '/js/lightbox_bridge.js',
        array('jquery')
    );
}
add_action( 'wp_enqueue_scripts', 'add_my_script' );

And added the following Jquery file (lightbox_bridge.js)

jQuery(document).ready(function(){
  jQuery('div.gallery').each(function(i) {
	jQuery('.bbg-img').parents('a').addClass('et_pb_lightbox_image');
  });
});

I haven’t had any luck so far… I’m hoping you can offer a more elegant solution. I would really appreciate it… Any suggestions you have would be greatly appreciated! Thanks in advance!

https://ww.wp.xz.cn/plugins/responsive-gallery-grid/