Purchased via Ubi shop. Download when where?

[Winger]

Hello everyone. I preordered the didital downloadversion of CoD iond February 2nd and already payed via paypal. Now i read that it whould somehow work together with steam. I have a steam account but up to now i didnt get any information on how steam will get the info from Ubi that i actually bought the game and have the right to download it. Also would it be nice to preload the game. I know the release is on 31th (living in germany here).

Thanks

Winger