Out of box with WordPress, there’s no functionality specific to galleries in the context of post types. There is the gallery shortcode but that’s just available functionality overall, even without custom post types. https://codex.www.ads-software.com/Gallery_Shortcode
So it really depends on how you want to do things. You could install one of many gallery-producing plugins available, both from www.ads-software.com or some premium shop somewhere else.
You could also potentially treat each post in a post type as an item in an intended gallery, and perhaps use some external tool or perhaps a javascript/jquery library that can create a gallery from items on a displayed page. For example a grid of photo thumbnails that when you click on one, it opens up in a modal popup, and has navigation between them.
None of this is available within CPTUI itself though, so there’s at least a little bit of work to be done regardless, and CPTUI isn’t the only component needed.
