Lobby as second scene

Hello everybody,

I want to use the NetworkLobbyManager and followed the instructions at the bottom of this page.

It says that I should set the lobby scene as first scene:
But I want to use the lobby as second scene, because my first scene should be the main menu. Isn't it possible to do so? When I try it, the NetworkLobbyManger isn't present in the hierarchy...

Lobby as second scene