Samsung Galaxy A12
Android 10.0
Select help topic
1 Find "Voice call"
Press the phone icon.
Press the menu icon.
Press Settings.
Press Supplementary services.
Press Call forwarding below the required SIM.
Press Voice call.
2 Divert calls to voicemail
Press the required divert type.
Key in +447836121121 and press Enable.
+447836121121
3 Return to the home screen
Press the Home key to return to the home screen.