WARNING: FRP unlock will erase all user account and phone data.
Put phone into Recovery mode
Phone must be turned off
Press & hold volume+ and power button, after logo appears, release the buttons, this will put your mobile in recovery mode
Select "Connect with MIAssistant" and connect usb cable. Make sure phone is visible on computer's device manager
Launch DC-unlocker client
Select Xiaomi from manufacturer's list and press detect button (Magnifying glass)
Wait for mobile to be detected
Open Server tab, enter your username and password that you received after credits purchase. Click "Check login". (you can buy credits here www.dc-unlocker.com/buy). This step is not necessary if you are a dongle user.
Now open "Unlocking tab" and click "FRP Erase" button
Wait for FRP to be unlocked
Now you can restart mobile to complete the process