Is there a way to turn on voLTE?

[Hansonj10]

Volte on a (sprint) flashed ULM with android pie

is it possible?

 

[maydayind]

Do your operator support it?
Operators can switch the funktion On your device

Problem with volte is that operators have to pay a licens to qualicom to use it and the licens is model specific. Lg g7 are not that common and menny operators don't whant to pay for a smal number of costumers and prioritise Samsung and apple. My operator supports volte but isn't going to pay for the licens of lg phones...