Enable WiFi calling

[NigelBl]

I live in Devon and the signal is worse than useless 90% of the time now. Coverage over the last few years and to have gone backwards.

I'm want to enable WiFi calling but haven't found the secret setting.

I tried the sky chatbot as soon as I asked about WiFi calling it kept trying to fix non existent broadband problems. 

I'm hoping that the community can do better than the chatbot. 

[PandJ2020]

Did you purchase your phone from Sky?  If so, what is it?

[NigelBl]

No a privately bought Android.  Redmi note 14 pro, running latest Xiaomi update.