Upgrade LineageOS on Xiaomi Mi 9T Pro/Redmi K20 Pro (raphael)

Manually upgrading LineageOS to a higher version of LineageOS

Warning

The updater app does not support upgrades from one version of LineageOS to another, and will block installation to any update for a different version. Upgrading manually requires similar steps to installing LineageOS for the first time.

Warning

If you previously had any Google Apps add-on package installed on your device, you must install an updated package before the first boot of Android! If you did not have Google Apps installed, you must wipe the Data partition (or perform a factory reset) to install them.

Verify your device is using the latest Lineage Recovery. Simply download the latest recovery file, named recovery.img.
Download the LineageOS zip file. Simply download the latest zip file, named lineage-21.0-xxxxxxxx-UNOFFICIAL-raphael.zip.
Now reboot into recovery. With the device powered off, hold Volume Up + Power. Keep holding both buttons until the “MI” logo appears on the screen, then release.
On the Lineage Recovery home screen, tap Apply update, then Apply from ADB for starting the sideload service.
Open a ADB & Fastboot tools window on your PC and flash the LineageOS install package you downloaded above:

$ adb sideload lineage-21.0-xxxxxxxx-UNOFFICIAL-raphael.zip

Information

Normally, adb will report Total xfer: 1.00x, but in some cases, even if the process succeeds the output will stop at 47% and report adb: failed to read command: Success. In some cases it will report adb: failed to read command: No error or adb: failed to read command: Undefined error: 0 which is also fine.

Information

Add-ons aren’t signed with LineageOS’s official key, and therefore when they are sideloaded, Lineage Recovery will present a screen that says Signature verification failed, this is expected, please click Continue.

Once you have installed everything successfully, click the back arrow in the top left of the screen, then Reboot system now.