This method is less reliable on modern, high-security firmware where Dahua has patched universal "master codes." 4. Modern Alternative: The QR Code Method
Depending on your model and region, there are two primary ways to use your serial number for a reset: Method A: Contacting Technical Support (Official Way)
Warning: This requires intermediate networking knowledge and will void warranties.
Linking a recovery email allows for instant resets via the DMSS app.