1 Find "Mobile network"
Slide two fingers downwards starting from the top of the screen.
Press the settings icon.
Press Network and Internet.
Press Mobile network.
2 Turn data roaming on or off
Press the indicator next to "Roaming" to turn the function on or off.
If you turn on the function, press OK.
3 Return to the home screen
Slide your finger upwards starting from the bottom of the screen to return to the home screen.