Wifi Calling Configuratble Provisioning Items What carrier specific software setting must be configured to properly enable wifi calling?  Clarification: I understand that wifi calling must be enabled, however, this is not a carrier specific software setting and is the same for any carrier.
Zero configuration is needed on iOS past turning it on or turning it off. 


https://support.apple.com/en-us/HT203032


All configuration on iOS is about extending the calling that works on your iPhone to other non phone devices. 

Hit up your carrier if you can’t turn on WiFi calling.