Adding excerpt and theme attributes to CPT

I need to add “excerpt” and the theme “attributes” (to assign a page template) to the CPTs generated by Custom Post Types UI. We use Elegant Themes’ theme Extra.

In looking under Tools > Get Code – I found this bit of code “useful if you wish to migrate away from CPTUI and retain your existing registered post types or taxonomies.”:
“supports” => array( “title”, “editor”, “thumbnail” ),

It appears that adding “excerpt” and (not sure if it’s …) “attributes” is the solution. But, I don’t know where this code is or how it should be modified since I’m not migrating anywhere just need to add excerpt and attributes in the current environment.

Help is appreciated.