Steven G. answered 09/23/22
Photographer and Instructor of Adobe Photoshop and Lightroom
Lightbox 2 appears to be a script that would just need your images to be hosted with the website. You would just export your images as jpg's, save that folder into your website directory, and add the path to that folder to the Lightbox script. There is probably a 'thumbnail' folder needed as well. So, you would export the full size images and the thumbnails separately. Exporting jpgs is simple in Lightroom. Click the Export button, choose the destination for the new files, pick your settings for the jpgs.
I am not a programmer, I can't help you with the Lightbox 2 programming.