Sokian

If you asked in the Sopranica MUC they would say Movim or Dino, you could even try https://app.cheogram.com/

Not self hosted but look at your local library, I am in the US and my library has Mango Languages for free, and Duolingo does not seem to be the recommended way to really learn a new language.

Also faircamp and mirlo.space

Also check out Adresilo which uses Maps api to find a location then can feed it to the app of your choice.

https://git.sr.ht/~amolith/adresilo/refs/v0.0.1-alpha

Nice, I setup a small VPS for it as a test, I need to redo it at home, its pretty neat.