There are many German members on my discord, they confirmed that they were able to activate the key without any problem, or without to use any "trick".
I have activated today and yeah it worked without problems. Yeah beeing able to play games like this is hard in germany, at least on steam lol.
Thank you for playing the game, i hope you'll enjoy it!
For now its fun but i think it still needs fixing because of clipping (butt is clipping through clothing of some outfits) and general improvements.