@Dony Have you claimed and/or bought any games? If not, you won't see anything. You need to install the Stadia app on your phone, then claim one (or both) of the games included in Pro sub, or buy a game, then they games will show when you go to stadia.com (assuming you already went through the code activation steps and all)
I think the problem is there being no scroll bar at all.
I've been trying to buy the game all day, but I cant seem to scroll down on any Stadia page