I use a VPN. fanatical stated available in the VPN countries I used but would not complete.
Different browsers, different accounts etc. Likewise when i disabled my VPN. Don't have access to a German VPN to test.
I went to fanatical.com - did a search for international-day-of-the-programmer-2023-free-giveaway Which gave me. https://www.fanatical.com/en/bundle/international-day-of-the-programmer-2023-free-giveaway