Bats are wild animals, and highly protected by the law. There is no legal or practical way to raise bats.
Here's a typical data point regarding legality of having or raising bats:
https://batworld.org/pet-bats/
You could become a trained/licensed wildlife rehabilitator, which would sort of give you a back door to have/raise a bat, or a few bats.
Alternatively, if you get to know your
local bats, and figure out what they want/like for housing, location, etc etc, you might get very good at attracting and encouraging the local bat population.
If you got good at it, that could be a service that you charge for...
You could be the Batman...