That is incorrect. It is technically possible to “host” a TLD with the proper private DNS servers, but a setup like that would only be usable internally- by you and anyone else connected to your network. I actually don’t think I’d recommend doing it at all in most cases, as it’s a huge hassle for something without much advantage.
Running a TLD/extension that other people can actually use to visit your website via the internet? That’s a lot more involved. I would go more into it, but I think the admin explained it well enough last time you brought it up.