07-12-202011:14 PM - last edited 07-12-202011:16 PM
the phone has to have the correct firmware too. if you purchased the phone direct from the carrier then it should work. if its direct from Samsung or a 3rd party like John Lewis it may not have the correct firmware for WiFi calling.
example... a Samsung A51 from Vodafone UK has wifi calling built in.
same model purchased from Samsung direct and putting same Vodafone UK sim in doesn't show WiFi calling option.
I am very sure you asked this question before and I answered it.