There's a city permit and a state license.

I've gotten the city license. It's not hard. You essentially do a demo for the fire marshall to show that you know what you're doing and follow good safety practices. The fire marshall has a fair amount of discretion with these permits, as I understand it.

The state license is a lot more complicated, and involves a significant written test. It's oriented towards people who operate fire installations, not firedancers. I have not taken it.