How to play multiplayer?

Hi everyone, I just bought FTG on gog and I would love to play with a friend of mine, but we could not figure out how to make it work.
I don't see any thread despite the 27 pages being shown.
Forgive me, Im just registrered and I don't know anything about this forum, I just want to play the game that i bought with my friend!
Please help me.

Thank you!

EDIT:
SOLVED - I just forgot to enable the firewall exception, sometimes the solution is right there but you can't see it lol