Because the MT6731 is a MediaTek (MTK) chipset, specific utility software is required to communicate with the hardware:
A standard MT6731 firmware package is typically distributed as a .zip or .rar archive containing several critical files: mt6731 flash file
If your phone is functioning normally, use OTA updates. If it’s bricked, you need the full . Because the MT6731 is a MediaTek (MTK) chipset,