Most of the Samsung phone comes with Volte support. However, if you had updated the phone with the Normal System update or tried to flash the phone which results in Volte missing.
It can be repaired easily by phone only.
- Dial *#272*Enter Imei no#.
- It will prompt a message on screen Preconfig. Under it Select INS & Click on install.
- It will take some time for installation and Volte will be updated.
In case if the phone does not have the INS file then it has to be flashed. You have to download Samsung Flash file & unzip it.
Then you have to select Home CSC under CSC tab in odin tool and flash.
Samsung phone can be flashed in download mode and make sure to install Samsung kies.