Not all OPPO A57s are the same. Check your current version in Settings > About Phone Older Model: Usually runs Android 6.0 (Marshmallow). Newer 4G/5G Model: Usually runs Android 12 or 13.
Avoid EXE “auto-flashers” from unknown blogspots. They contain viruses. oppo a57 china to global firmware
: The process typically takes about 10 minutes to write the new system files before automatically rebooting into the global environment. The "Soft" Alternative (No Flashing) Not all OPPO A57s are the same
The Oppo A57 was initially designed for the Chinese market, where it was launched on December 13, 2016. The phone boasted a 5.7-inch HD display, a 13-megapixel rear camera, and a 16-megapixel front camera. It was powered by a Qualcomm Snapdragon 435 processor, paired with 3GB of RAM and 32GB of internal storage. The device ran on ColorOS 3.2, a customized version of Android 6.0 (Marshmallow), which was specifically designed for Oppo devices. Avoid EXE “auto-flashers” from unknown blogspots