I had recently had a hand on my friends Moto X force 1580. The phone works on android 7.0. I went through web found out some guys claiming to make Moto x style to work on VoLTE i followed the same procedure but had no luck. Following is the procedure that I went through.
1> Dial ##4636##
2> A hidden menu would start select Phone Information
3> in this window there is a switch that says
VoLTE provisioned this by default is off turn this on
4> restart the phone.
I tried this number of thimes but it turns back off every time. can any one help.