If there are no trainings in your area, you can consider being a host facility. We have regular B1 trainings at a nearby location, but I’ve hosted Zumba Toning, Zumba Gold (3 times), and am about to host Zumba Step. If you’re in a well-populated area you might just get a training nearby. If you’re not in a well-populated area, you might have to consider traveling to get your license.
I agree with Janet’s suggestion to get a group-ex certification in addition.