@floem7 said in Unlock Bootloader – How To Unlock?: Second question, how can I backup my original android 11 in case I've screw something? No recommendation for a backup. You can use the Rescue and Smart Assistent from Lenovo (RSA) to reinstall latest stock Android. Sadly, this tool is only available on Windows. A good strategy is to use RSA to download the firmware file, and save that file. The path is shown in the upper right corner of the UI while the file is downloaded. Either you are fast enough and you can copy the .zip file, or you need to zip the unzip directory yourself. This firmware file contains all the partition images of the devices, and you can flash them via fastboot to restore Android. Kai