Download the Bell application. Before opening the App, you have to open some permissions of the phone before you can use it normally.

Open i housekeeper-software management.

Turn on self-start management and select ringtone sensing-make sure to turn it on and ensure that the video ringtone can be used normally;

Space.

Open the floating window management and select ringtone sensing-be sure to open it to ensure that the video ringtone can be used normally;

Space.