The flash on your Huawei device can be turned on, off and on automatic mode. If the device is set on automatic, it will decide when a flash is needed using the built in sensors. To set this up, you need to tap on the flash symbol in the camera app.

Android 10 | EMUI 10.0
Flash -  Open  Camera
Flash -  Tap on  Flash
Flash -  Choose between  on ,  off ,  automatic  or  always
  1. Open Camera
  2. Tap on Flash
  3. Choose between on, off, automatic or always

Huawei Instructions