There are several UI translation projects, one is Transifex. There is also Crowdin, but I see they have started using “AI” translations as well…
Generally, both mobile and web apps that are interested in volunteer translators will have a link to their preferred platform in their source code repository.
This message doesn’t say anything about the validity of your license, though. Or am I missing something?
I’m not up to date on Windows versions, but saying Win 11 has reached end of service is… unexpected?