Not have VoLTE in my N950F

[azoter]

Hello
My N950F smartphone does not have VoLTE enabled.

How or with which ROM / Firmware VoLTE is enabled

I have Oreo

Thank you very much in advance

 

[winol]

I have a 950F 128 GB, and it came out of the box with no volte enabled, I received a message a month later from my carrier telling me that volte was available for my device but I had to take my device to them for activation, and that was it, I took it to them , they changed the sim card and now volte is active and available, to make this clear, I bought my device from my carrier in prepaid mode, so it is branded but unlocked for any carrier