Download Custom Recovery to your REDMI 9A device or check Google if no one find it on this page.
Manual how to choose your custom recovery example on Redmi 5 Plus:
Scroll down to the download link and tap the primary (europe) link.
Tap the download link with the latest version means the first one on the list.
Next again tap download link to get custom recovery to REDMI 9A on your computer.
WARNING!
Root process on the REDMI device will erase all of your data.
All described operations you are doing at your own risk.
If want to save your data do a backup before starting.
The battery should be at least 50% charged before the start.
After complete factory reset operation phone will reboot and turn on to welcome creator, then turn off REDMI 9A by the power button and option from the pop-up menu.
Turn off antivirus on your computer because lots of it think that a custom recovery file is a virus and is not allowed to download it and use it.
Make sure that you are using the default directory of ADB and FASTBOOT. If didn't change the path, you can find files in C:\ADB
Copy downloaded custom recovery to default ADB and FASTBOOT directory mean C:\ADB if not change path.
Rename custom recovery name to recovery.img
Copy magisk manager application (magisk-v23.0.apk) to the microSD card.
Rename the magisk manager application file on the computer to magisk.zip and copy it again with a new name to the microSD card.
(on microSD card should be 2 files 1 zip and 1 apk)
