Everything seems installed and ready to go, but when attempting to log online, game is blocked by the need for a required CD Key set of numbers. In past NWN games, those CD Key codes were available in a game folder. I have hunted through every folder that I could find to no avail. I am trying to get my brother involved in the NWN online community and this seems the last hurdle. Any help available, please?

This might help.
https://www.gog.com/forum/neverwinter_nights_series/multiplayer_solution_invalid_key_enhanced_edition