Who is the host of relay in unity

First question:
When you create a relay and create a host using function “NetworkManager.Singleton.StartHost();”, is the player prefab (isnside Network manager prefabs list) a host, or is it the instance of the game that is the host.

Second question:
How can you check if the player is the host of this relay. I’m trying to make start button (like in Among Us), where only the host of the game can use it and start the game, and i can’t figure out hot to make the button only visible for host. Please help