>>507You can self host it but you don't have to. It is just a front end proxy for different translator sites like Google, DeepL, DuckDuckGo, MyMemory, Reverso and sometimes others depending on the instance. Here is one so you can get an idea what it looks like.
https://mozhi.pussthecat.org/Firefox has a built in local translator that does not reply on servers but it doesn't work that great for Japanese.