In The Sohnland, there is an 'official' route for citizenship; However, it has never worked for anyone.
Obtaining citizenship is guaranteed if you are appointed as such by the Supreme Leader or invited by another Sohnlandic citizen. You will be presented with official documentation confirming your status as a citizen and can receive national ID cards, your very own passport and other benefits.
Citizenship isn't just given out to anyone, it rarely ever is. To increase your chances of being appointed or invited, it is recommended that you have extensive knowledge about The Sohnland and be trusted by the Supreme Leader.