Extra feature settings for post types
On top of being able to add any post type to the main "Blog" posts query, CPTUI-Extended also allows you to add your post types to a variety of other archives or features.
These setting can also be found at the bottom of the post type's add/edit screen when Custom Post Type UI Extended is active. All the features are also available on the network-wide post type settings for each post type. Checking this setting at the network level is going to make the chosen post type automatically appear in the query in ALL sites in your network.
Once you check any of the options and hit add/update, the post type you added it for should automatically start taking effect.
Default category archive
If you have added category support via the "Categories" that WordPress core ships with, checking this option will add the post type to the query when visiting the term archives for that category. This makes WordPress query for more than just the "post" post type.
Default tag archive
If you have added tag support via the "Tags" that WordPress core ships with, checking this option will add the post type to the query when visiting the term archives for that tag. This is just like the category archive above, but for the tags instead.
Google AMP support via AMP
Divi Builder support
If you are a Divi user, and utilize Divi Builder to manage your site, then checking this setting will help add support for your custom post type inside of Divi Builder. This setting requires Divi version 2.4 or higher.