Where do I get Flonase (allergy spray) without prescription?

Mexico, maybe. It will probably be cheaper to see your doctor and pay for the office visit and prescription than to travel to some country where nasal steroid sprays are available over the counter. However, I'm not specifically aware of any country that makes any of the nasal steroid sprays available without a prescription.
No need for Rx. Flonase is now sold over the counter at most pharmacies without a prescription.