1. Find "WiFi Calling"
Slide two fingers downwards starting from the top of the screen.
Press the settings icon.
Press SIM card & mobile data.
Press the required SIM.
Press WiFi Calling.
2. Turn Wi-Fi calling on or off
Press the indicator next to "WiFi Calling" to turn the function on or off.
3. Return to the home screen
Press the Home key to return to the home screen.