It's right there at the obvious place for me (who pre-ordered last night): https://www.larianvault.com/accountgames.php
If you don't have any Steam key (and faulty beta download button) there, I guess you haven't been included yet.

Proud Probatanthrope

Tor.com: Boob Plate Armor Would Kill You (cf. "ball plate armor" - Just think about it.)