Steam server questions

  1. How can i create server hosted on client for coop playing? People can connect only using steam friends/join
    I tried to do this using advanced steam session but there doesn’t appear invtite friend
  2. Shoud i buy server to have in my project coop, or there is enought steam subsystem?
    I need my players can connect to his friends without opening ports, knowing ip, etc. I want my game like cs:go lobby serves or like in this demo project Steam Party in Code Plugins - UE Marketplace