Hi
shalihinyinKindly refer to 4 main requirements below that needs to fulfill to use VoLTE function :
A. The carrier supports VoLTE
B. The carrier supports VoLTE with the model
C. SIM Card has VoLTE
D. Both side are using VoLTE
First, please check with your sim carrier weather it supports VoLTE in ZS600KL or not. Thank you.