Do not use random firmware from torrent sites. They often contain outdated prog_emmc_firehose files that can permanently damage your eMMC chip.

For a QFIL flash, you typically need or a programmer Firehose loader file. This guide will reference verified sources that provide usable files for the CPH1801.

The "interesting" part also carries a warning.

Using the OPPO A71 CPH1801 QFIL flash file offers several benefits: