As this is a Network driven feature I'd suggest to contact Vodafone Customer Support or their Vodafone Social Media Teams via Facebook Messenger or Twitter DM and ask them to send an OTA ' over the air configuration ' so the files are sent to the phone and then you should see the settings in the phone to activate.
" If you can't turn on WiFi Calling on your phone, check that it's turned on in your My Vodafone account:
Did Vodafone supply the phone directly ?
I ask because on their support pages Vodafone state " All these phones support both WiFi and 4G Calling when bought from us. Please note that phones bought from other UK network providers and third parties are unlikely to support Vodafone WiFi and 4G Calling – with the exception of iPhones, which should work regardless "
I wish you all the best. Take care. 😎
Daily Driver > Samsung Galaxy s²² Ultra 256Gb in Phantom Black.
The advice I offer is my own and does not represent Samsung’s position.
I'm here to help.