Hello :)
You can remove that limit, but i do not recommond doing it, because the game codes handles 7 players only currently, player 8 and above will break everything in the game, you will have to handle all players in the codes in order to make them not break the game rules.
Open the Lobby scene events → Server code event → Spawning players → A client has connected event → State.HowManyPlayersHasJoinedTheLobby → currently its 7, change that to the number of players you want. to be in the lobby.