I cannot repeat the process to check, but I was able to ship to Poland, so why not Germany listed? Also there was some issues with street as it continuously added the prefix proposition, so I typed a State in Address 1 and Street in Address 2. Then it was valid, but I had to change it at summary, so the address rows are correct. Lets hope it will arrive at right place 😉
Facebook stopped selling to germany last year:
VR Cover also make Quest 2 silicone covers. They are usually €14 but are 50% off for the next 3 days and have world wide shipping.