Thus, 727.43 indicates a build from , likely year 2024 or late 2023, depending on internal iteration. The ".43" suggests it’s a slightly refined build from an initial July 27 release.
: You must bind your Mi Account to the device via "Mi Unlock Status" in Developer Options using mobile data (not Wi-Fi).
The is an official utility provided by Xiaomi specifically for unlocking the bootloader of Xiaomi, Redmi, and Poco devices.
Power off the phone and hold the Volume Down + Power buttons until the Fastboot logo appears. Connect it to the PC via USB.