Mi Max 3 (xiaomi-nitrogen)

Recovery

 * Turn off your device;
 * Press and hold “Power“ button and “Volume Up” button;
 * Hold both till Mi logo appears;
 * After the Mi logo appears, release “Power” & “Volume+”
 * Welcome to Recovery!

Fastboot Mode
sudo ./fastboot devices
 * Turn off your device
 * Press and hold “Power“ button and “Volume Down” button;
 * Hold both till Mi logo appears;
 * After the Mi logo appears, release “Power” & “Volume-”
 * After booting into Fastboot mode, connect your device to a Linux desktop using the original USB Cable;
 * Open Terminal in the SDK location, check your device is connected with: