The first thing you'll need to facilitate your networked game is a NetworkManager component. This component handles most of the functionality associated with multiplayer settings and states, including connecting, disconnecting, hosting, joining, and spawning.
Create a new empty object in your lobby scene and name it NetworkManager. Add a NetworkManager component to it in Inspector:
Ensure that the first property, labeled Dont Destroy On Load, is checked. This property prevents the object that this component is attached to from being removed between scenes, so it will still be present in your game even if you switch to a completely different scene (that is, one of the maps). This will make it easier for us to enter a new scene and still have access to the NetworkManager component's information, and we can use it when the match is over to return to the original scene.
Notice the two fields labeled Offline Scene and Online Scene. The Offline Scene is the scene loaded...