You hit auto and find a relatively dark environment and see.
And then, there's a button on the left side of the flash, press and hold him to turn the wheel. See if you hit the flash to the no flash option. It will show up on the right side of the shoulder screen, and if the flash logo isn't disabled, something is wrong.
It is recommended to take the warranty card, and proof of purchase to the after-sales to have a look.