Please tell us some basic information before asking for help:
Model Name: Zenfone 5z (ZS620KL)
Firmware Version: WW_100.10.107.123_20210131
Rooted or not: Not
Frequency of Occurrence:
APP Name & APP Version (If your issue relates to the app):
In addition to information above, please also provide as much details as you can, e.g., using scenario, what troubleshooting you've already done, screenshot, etc.
========================================
There is no option to enable VoLTE for Malaysia carrier.
Malaysia will shutdown 3G at the end of 2021.
This need to be enabled by firmware update?