Back Light on Nikon D3200?

There's no Backlight function.
How do you get the flash to operate manually?
IB

Switch from the green auto mode to P for program and push the little button next to the flash to get the flash to pop up.

When you are on the green auto setting the camera tries to do everything for you including popping up the flash.

When in P mode, the ISO setting is probably not going to be set to auto, so you will need to set that as well.

Apart from that, the P setting will operate very similarly to full auto, except that you can over-ride the camera's choice of shutter and aperture settings by using the thumb wheel if you wish to.