Here is the reality check: True "PC-less" unlocking for this phone is rare. Most methods require a PC for the initial fastboot commands. , if you are already on a custom recovery or a hacked stock ROM, you can bypass the PC. For a clean, stock device, you need a workaround.
Typically, Asus provided an official unlock tool, but that required a PC. However, as the device aged, developers discovered exploits that allow unlocking .
Disclaimer: Unlocking the bootloader will wipe all your data (photos, apps, contacts). It also voids your warranty and makes your device potentially less secure. Proceed only if you understand the risks. This method requires specific app versions and an internet connection.