How do I ensure the device works on Android when the screen is locked?

1> Open the App on your home screen before you lock the screen.

2> Add the app to protected apps or your white list on your phone.

Other
How do I open permissions on Android?
How do I open permissions on an iPhone?
How do I ensure the device works on Android when the screen is locked?
After upgrading ios 11, turn on Bluetooth, why is APP still reminded that Bluetooth is not enabled? How to deal with it?