Samsung Galaxy Z Flip4
Android 12.0
1 Find "Message Centre"
Slide your finger upwards on the screen.
Press Samsung.
Press Messages.
Press the menu icon.
Press Settings.
Press More settings.
Press Text messages.
Press Message Centre.
2 Enter the message centre number
Key in +6421600600 and press Set.
+6421600600
3 Return to the home screen
Press the Home key to return to the home screen.