Originally posted by Виталий(Батя):

Для ачивки сыграть по интернету и как добавить 50 друзей опять же для достижения?

The lower left button on the main screen of the game will show a list of characters; when selected - the game will ask for Internet or Lan - as Internet can be selected after a Runic Account is made and a Room can be made or searched.

If Multiplayer doesn't function for some reason then there's the Port Forward method which requires the Lan option:
https://steamhost.cn/steamcommunity_com/groups/TLM2H/discussions/10/2785991200453324508/

As for the 50 friends - simply write random names until the achievement is reached.