Hi Wojon! Thanks for trying.
You'll need three players at the very minimum (this game doesn't make sense with two player), although the more players - the better. The core of the game is cooperation and planning, trust and betrayal for which you don't have much options when playing with few players.
All players need to log in with their Google accounts.
One player creates a room (open dialog with button at the bottom of the left column), when you select a room from the list of your rooms (left column), you can see "Room ID" at the top-center of the page - send it to other players - they need to paste it to join (also open dialog with button at the bottom of the left column).
Or you (both) can join the room I created for public use: 5Mf4Qwyh0UFQV83qBhUY
Once there are three or more people in the room, "room creator" will have a button at the top of the room to start the game.