OPPO A72
Android 10.0
1 Find "Call Forwarding"
Press the phone icon.
Press the menu icon.
Press Settings.
Press Calling accounts.
Press Carrier Call Settings.
Press Call Forwarding.
2 Divert calls to voicemail
Press the required SIM.
Press the required divert type.
Key in +447836121121 and press On.
+447836121121
3 Return to the home screen
Press the Home key to return to the home screen.