I tried to get the plugin to work with 2024 (WP default) and pasted
do_action( 'wp_nav_menu_item_custom_fields', $item_id, $item, $depth, $args, $id );
in wp-admin/includes/class-walker-nav-menu-checklist.php and noticed that $item_id $item $id are not in the scope of start_el with a comment that two of those names were changed circa wp 5.9.0
I couldn't get the menu to show up in wp-admin menu to config. I have used with 2021 theme some time ago and it worked great. Thanks btw :)