Other Unity matchmaker with fusion dedicated server for player limit in room

We have game where game should start(game play Level load) if only if there are min 2 player and max 16 player in room within 30 seconds. If there are less then 2 player game should not start.
How we can get player count before start game while waiting using matchmaker and multiplay.
We are using matchmaker, multiplay and fusion dedicated server, what is the best way to limit player count.