Huawei P40 Pro
Android 10.0
1. Find "Voicemail"
Press the phone icon.
Press the menu icon.
Press Settings.
Press More.
Press Voicemail.
2. Save voicemail number
Press Voicemail number.
Key in +447836121121 and press OK.
+447836121121
3. Return to the home screen
Slide your finger upwards starting from the bottom of the screen to return to the home screen.