Posts from Network game key.

I know there was a topic about this, but it's currently closed. The question is: today I bought Heroes of Might and Magic 5 from an online store. They sent me the game key. I downloaded the game from their site, installed it, entered the key, and activated it - everything was fine. But when I try to play online, it asks for a network key. When I contacted the store's technical support, they told me that it is not provided in electronic form. What should I do and where can I get it in this situation? Thanks in advance.

Added after 19 hours 28 minutes
I figured it out.