The key is currently available for free on Fanatical.

https://www.steamgifts.com/discussion/TYyco/steam112-operatorfree-until-feb-03-0000-utc-or-out-of-stock

According to the thread above, the key works worldwide even though the Fanatical giveaway is regionally restricted.
So I'm giving the key away to people in the unavailable countries, so that you can get the game too. Hopefully the key will indeed work, as the thread says.