To flash this device using QFIL (Qualcomm Flash Image Loader), you generally need:
In this state, you need . This is a low-level flash package containing partition images (boot, system, recovery, modem, etc.) specifically structured with: oppo a3s qfil firmware cph1803 qfil flash file link
Power off your device. Hold Volume Up + Volume Down and connect it to your PC via USB. The tool should show "Qualcomm HS-USB QDLoader 9008". To flash this device using QFIL (Qualcomm Flash