Not checking existing slugs

The problem with this plugin is, it doesn’t check to see if another post or page already has the same slug.

I created a CPT, and updated the permalink to be /%post_name%/. That’s also the same permalink structure for Pages. So if a Page already has a slug of /example/, the problem is the CPT isn’t checking to see if that already exists, and therefore it allows you to still create a CPT post with that same slug. This is not ideal.

There needs to be some way for it to check existing slugs, and to append -1 at the end, if it sees itself as a duplicate.