: You need a custom recovery like TWRP to flash the ROM files.
: This is the most critical step and often requires specific tools for OPPO devices. oppo a11k custom rom link
: It is highly recommended to have your official stock firmware downloaded as a backup in case the device bootloops. Important Safety Warning : You need a custom recovery like TWRP
You can find these on SourceForge or dedicated telegram channels for OPPO MTK development. 4. Flashing the ROM 10 Best Custom ROMs for Android You Can Install - Beebom oppo a11k custom rom link