Creating AR experience in Multiplayer Game

Hi,
I am working on a multiplayer game and using NetworkManager, NetworkManagerHUD on my UIScene which loads when the game starts. In the Play scene when players join the lobby, I want to show real world through device camera, and on top of that players' avatars should appear.(Kind of AR experience)
I have tried giving Main camera (0,0,0,0) but not able to see transparent camera and the canvas looks black.
How to achieve this?
Thanks,
Meghaksh