How does Apple's mobile phone turn on the flash function of the camera?

Take Apple's 1 1 mobile phone as an example. When the camera is used in the mobile phone, the flashlight will be occupied by the camera by default, so it cannot be turned on. As long as you get back to the desktop, you can use the flashlight. The operation method is as follows:

Device: iphone 1 1

System: iOS 14.4

1. Enter the phone and click to select the camera.

2. On the camera page, slide down to enter the menu, as shown in the figure below:

3. When the camera is turned on, the flashlight cannot be turned on, as shown in the following figure:

4. After turning off the camera, you can turn on the flashlight, as shown in the figure below: