Anthony

Tailored Media

WordPress plugin to enqueue <a href="https://fancyapps.com/fancybox/3/" rel="nofollow ugc">fancyBox3</a> lightbox script.
Should work automatically, any links to .jpg, .jpeg, .gif, .png will become lightbox links.
Current version: 3.5.7

Tailored Lightbox

I can even have the lightbox effect with the native Gutenberg galleries.

Thanks.

Works Perfectly !

Enqueue the Fancybox lightbox script, and automatically load for links to image files.

omerk

<a href="http://fancybox.net/" rel="nofollow ugc">Fancybox</a> is a tool for displaying images, html content and multi-media 
in a Mac-style “lightbox” that floats overtop of web page. It was built using the jQuery library.
This plugin inserts the necessary elements required to run Fancybox on your blog. It also groups 
images within posts using rel attributes. (Based on the code found on <a href="https://wordpress.org/support/topic/automatic-adding-lightbox-rel-and-group-to-images-in-posts" rel="ugc">this</a> 
forum thread)
To disable Fancybox per post: Add a custom field called ‘nofancybox’ and set it’s value to ‘true’. 
Instructions on how to add custom fields to posts can be found at <a href="https://codex.wordpress.org/Custom_Fields" rel="nofollow ugc">this</a> 
codex article.

Fancyboxify

This simple plugin enables Fancybox on image links. It groups all images within a single post and can also be disabled per post.

Tailored Lightbox vs Fancyboxify