Why didn't Huawei see the function of healthy use of mobile phones in P9 settings? Emergency help.

Open "Settings". Click notification bar and status bar > notification center, and select the application for which you want to set notification mode. Various notification methods to open or close the application as needed. If the system application icon is missing, please confirm whether the application is in the "deactivated" state. Go to settings > application management >; Menu > display system, find the application in the application list interface, and adjust it to enable.