To put it briefly:
Huawei P9 Lite needs a hard reset.
I looked at tutorials.
In all tutorials, the mobile phone was switched off, then the power button and volume up button were held down until it vibrated. Then you should let go of the power button but not the volume up button until you are brought into recovery mode "EMUI".
There should be an option where it says: "hard / factory RESET"
But in my case it stands
EMUI
Update latest version
reboot
Shut down
But I want to reset the cell phone. The function should be in recovery mode, but it is not for me.
Go to the settings, there you will find the item backup and restore and the item reset to system & updates