Xiaomi Mi 11 Ultra
Android 11.0
1 Find "SIM cards & mobile networks"
Press Settings.
Press SIM cards & mobile networks.
2 Turn Wi-Fi calling on or off
Press the required SIM.
Press the indicator next to "Make calls using Wi-Fi" to turn the function on or off.
3 Return to the home screen
Press the Home key to return to the home screen.