ok so flame is in new tank I was told uvb light outputs down so his basking spot needs to be directly under but it has reflector on the fixture so I'm assuming it gives the output more coverage is this correct? or do I need to get his basking spot underneath it which will be hard since its mounted on the tank back side glass
The reflector concentrates the output over an area where the reflector is pointing, and makes the output effectively stronger. If you can move the reflector, you'll want it facing down over the basking area. Otherwise it will be best to move the fixture so that it is overhead and the reflector is shining down over the basking area rather than outward in order to maximize the UVB output over the basking site.