If you cant help just be quiet , i have more than 15 years experience in this domain , and its a commun problem with rog 3 , i have a cn model never unlocked with cn fw and hence not able to unlock it , im the guy behind bs3/3pro/3s unlock method and firmwares .
Firmware (stock/ custom) is usually in default form of .zip file, which can be flashed via various ways including TWRP;
(for latest stock firmware) just placed in the root of the Internal Storage - your device should detect it automatically & install it.
A RAW file (different format) of a ROM (stock or custom) can be installed via fastboot commands while connected to PC. This usually takes longer compared to flashing a .zip firmware, and is a more thorough install of ROM especially if standard .zip installation is messing up/ problematic.
Updated mine tencent version converted to WW by seller to newest Android 11 rom placing zip file in root folder.
I wish to revert back to android 10 but can't unlock bootloader with tool provided by asus nor with fastboot :/
Should I flash it with fastboot raw firmware to get A10 back ?
edit: Just after loading raw image of Android 10 and it works as expected
edit 2: After flashing raw firmware unlocking tool works as expected! Got my bootloader unlocked with official tool 9.3