Samsung Galaxy S21 5G
Android 11.0
Select help topic
1 Find "Mobile networks"
Slide two fingers downwards starting from the top of the screen.
Press the settings icon.
Press Connections.
Press Mobile networks.
2 Turn data roaming on or off
Press the indicator next to "Data roaming ‹SIM›" to turn the function on or off.
3 Return to the home screen
Press the Home key to return to the home screen.