Start by linking your Steam account with the Paradox forum. The very very first message at the top of the forum page tells you how. That will let you see the technical support forum. Once you're in the correct forum, read the very first message at the top of that forum; it gives guidelines on how to post in such a way that you include the information needed for others to be able to help you solve the problem. Then make a new post that includes the suggested information. Or if this post has not yet been locked, which I expect it will be quite soon, you could PM a moderator and ask that this thread be moved to tech support, then you could edit it to add the missing information. But nothing useful can happen until you link your account, which registers your game automagically.