The safest way to flash TWRP the fiest time is do the following requirements. That way people don't mess up the process or their devices.
1) Flash lastest TWRP unofficial 3.31-4 mauronofrio using Command prompt using the - fastboot flash recovery [XXXX].img. Note: it's easier to just rename the recover image to "twrp"
2) Then - fastboot boot [XXXX].img
3) In my experience, the reboot to RECOVERY did not happened, so instead i pressed - volume up and power button at the same time until you see the boot splash screen, hold the two buttons for another 3 seconds... and then let go of power button and then TWRP recovery will show up.
4) Ok...so first things first... flash the VBMETA PATCHER like the OP says --> that way you don't lose TWRP after flashing MAGISK. After install, reboot to RECOVERY.
5) Now....go to FORMAT DATA (Warning: DON'T use advanced wipe)... Instead, go to the FORMAT DATA, type in yes and press ok. Then go back to main menu, and reboot to RECOVERY again.
6) Now you can access your internel memory when connecting to USB... You can import the two neccesary files --> Xiaomi.EU and MAGISK 20.4. Now Flash the Rom and when flash MAGISK, make sure you unmount DATA and mount VENDOR to avoid flash error. After unticking DATA, you can now install Magisk.
7) Now you can go to REBOOT, and press SYSTEM, and the phone will boot to Xiaomi EU 11 or 12, etc. Just follow this process and enjoy your ROM. ?
***When updating a Rom, just flash the Rom and Magisk (don't foget to umount Data when flashing Magisk)