Board Thread:Support Requests - Getting Technical/@comment-38575539-20201016162526/@comment-9605025-20201016181433

What SapadorCastelo linked to was the help page for galleries in general. Most of the gallery functions are for use outside of infoboxes so that page is going to have a lot of information you don't need. For using galleries in infoboxes to get tabbed images, see here.