Do I need a player prefab spawn to use Unity's HLAPI System?,

I’m making a 2-D multiplayer game similar to Civilization 5 in where there is one city in which two players interact with. The plan is to use Unity’s HLAPI System to have the game running on two screens, one for each player with the same map on each screen. A change one person makes to the city will appear on the other player’s screen. The problem is that I keep getting an error telling me to add a player prefab to the network manager. Do I need a player prefab at all? If so what would I spawn in my case? Are there other options besides Unity’s HLAPI?

EDIT: Would a camera work as the player prefab?

Yes it does need a player prefab i bet u got a camera? Make it a prefab and spawn it