SuperTokens is an open source authentication solution offering features like: Different types of login: Email / password, Passwordless (OTP or Magic link based).

SuperTokens.com

Hey, any plans on supporting multi-language email templates?

Hey. You can achieve this by overriding the emailDelivery config on the backend. See that section in our docs please.

But there is no "official" translation thing where we could contribute for all users?

Yes, there isn’t anything “official” other than what I mentioned