Not global, keys are dependent on region however you can check the country list here: https://us.gamesplanet.com/community/elden-ring-steam-key--4266-1/discussions/255383-elden-ring-region-restictions-for-steam

If you buy from the US website it'll work in your region. Can't speak for other websites maybe they have different region keys (there's no global key) but ours work for you.