Hi there, @haiper_safi… the short answer is you can’t reuse names of deleted apps, and nobody in the forum can help you with that.
As Eve mentions in the answer in that thread, it might be worth contacting support to see if they can help.
Also, as Adam mentions in the second-to-last post in the thread, it doesn’t really matter what the name of your Bubble app is because once you put the app on a custom domain, users won’t see the name of the Bubble app anymore.
Best…
Mike