Huawei MATE 9 Use Manual page 176

Turning off the flashlight
Turn off the flashlight after use to avoid draining the battery.
1
Swipe up from the bottom of the lock screen to display lock screen features and tools.
2
Touch to turn off the flashlight.
When the screen is unlocked, swipe down from the status bar and touch
l
the flashlight.
Alternatively, open Tools and touch Flashlight >
l
.
Tools
to turn on
170