How do I add a new civ to the game using fire tuner?

[iammaxhailme]

I know how to give units and such to already-spawned civs, but I don't know how to add a new civ (specifically, I want to add a certain city state to the map). I see in one tab you can initialize a player as human or AI, but I don't know how to actually assign that player slot a civ/city state after they are initialized.

To be clear I mean I want to add Nazca. I'm not involving making new content, I just want to figure out how to spawn them on the map on turn 1.