I can't use early access

I logged into the POE2 website using a steam account and bought an early access kit. It turns out that now I can’t use this in any way. The standalone version requires an email and a password to play (I don’t have them, I logged in through Steam). You can’t play through Steam either. The key adds the game to my library but does not give access to early access! How can this be and what did I end up gaining? Essentially, I purchased something that I cannot use for its intended purpose. Why didn’t they warn me when purchasing that I couldn’t use the purchase for its intended purpose if I bought access logged in under a Steam account on this site?