I'm not an expert. I'm asking because I don't know.

Did I understand correctly? You can create a site with a .onion extension without a domain on a hosting service.

I'm thinking. If you can do it this way with .onion, can you do it with something else? That would be a bit unusual.

If that were possible, being able to customize the extensions would be interesting. Being able to customize brand names. Like .mybrand, or .egg, .bread, whatever you want.