In Texas you're not supposed to do ANY fire alarm work without the proper license and insurance.

All fire system installations are supposed to follow NFPA codes.

Required by the State or not I definitely wouldn't touch a fire alarm or anything pertaining to fire protection without sufficient commercial liability insurance because by doing so you are assuming a very large responsibility.
If you did something wrong and a building burned
(or worse) as a result you could find yourself in a sad situation.