You just install the zip, and reboot.
Some people like to clear dalvik & cache, but it should be done automatically.
The updater download the zip, and try to reboot to TWRP to install it, but depending on your phone model, the process can fail at some point, and you can do it manually.
Only one suggestion is to load TWRP in memory and flash your update. You don't need to have TWRP resident in your phone. From Twrp flash your update save in one of your folder or from a usb stick. Make a Dalvik clean cache.
I'm not sure but I think there is a small bug between the boot partition and the system partition of the MI 10 pro.
That's why load TWRP in memory is more sure and then flash your update will work correctly.
I see what you guys mean. I just updated to the latest 21.9.15 Weekly/Beta ROM according to your instructions.
Let me list out the process to help those who don't know
how to update MIUI EU without flashing/installing TWRP beforehand (With Fastboot boot method):
Note: If you are updating from
Weekly/Beta to Stable or
Stable to Weekly/Beta version, please refer to this guide:
https://xiaomi.eu/community/threads...redmi-k30s-ultra-thorough-step-by-step.61742/
Please make sure you have downloaded suitable
TWRP for your phone and
Minimal ADB and Fastboot is installed on your computer, and your TWRP file are placed in the folder of Minimal ADB and Fastboot.
1. Connect your phone to a computer by using a USB cable.
2. Turn off your phone and then boot into Fastboot mode by pressing Volume Down + Power button.
3. Run Minimal ADB and Fastboot on your computer, type "adb devices" to ensure that your phone is recognized by your computer.
4. Type "fastboot boot TWRP.img" (Follow your TWRP file name, e.g. umi.TWRP, "fastboot boot umi.TWRP"). Your phone should be able to boot to TWRP after the command is issued.
5. If TWRP asks for a password, just click Cancel. Go to Wipe > Advanced Wipe > select Dalvik/ART Cache > Swipe to Wipe. When the wipe process is complete, return to the TWRP home page.
6. Go to Install and select your ROM zip file > Swipe to confirm Flash. The process of flashing will begin. (Please make sure you have downloaded the ROM zip file to your phone's internal memory or USB OTG).
7. After the flashing process is complete, reboot to system. Your phone will finish booting in about 5 minutes.
The update process is complete until here. Feel free to let me know if there are any errors in the tutorial. I hope this can help newbies in need.