Apple 12 video has fill light, why not 13?

Reason: In automatic mode, only when the light is bad will the light be automatically replenished. Or the flash is off. How to turn off the flash:

1. Turn on the Apple phone and enter the camera.

2. Enter the lightning sign in the upper left corner and turn it off at the auto, on and off points.

When the camera is displayed next to the lightning sign, it means that the flash has been turned off. So there won't be a flash for taking pictures. In addition, when the light is turned on automatically, when the ambient light is insufficient, the flash will be turned on automatically to fill the light. If the light is good, there will be no flash when taking pictures.