I have attached a doc based on 10ultra but it will help as the method is the same, just using different files. Unfortunately the links in the pdf may not work but as yours is not the 10 ultra, it's not going to matter as I get files from the mifirm link further down this post.
The EU ROMs after the very first fastboot versions are all twrp .zip files, so you have to get a working twrp installed first. The problem is that the Chinese ROMs have the ability to overwrite twrp unless you boot to it and install your ROM straight away but you can install it via fastboot, reboot to recovery to test that it installs and go back and install it again from fastboot and go to it when you are ready to install the EU ROM.
Make sure you have an off phone back up or ability to get to your data if you want to save it as it will need a data format as I said above. I notice there are 2 twrp versions for your model, so make sure get a good working one. I always use
http://mifirm.net or from the download links from this forum. See if anyone else has installed it ok, just in case there is a mismatch issue again before you start.
When your ready, get your twrp in the adb fastboot folder on the PC, connect up the phone, power off the phone and power on and volume button down to enter fastboot. Install twrp, reboot to twrp, install ROM by mounting PC and selection ROMs .zip file or by usb, however you stored it. Once flashed, format data, not just wipe ( some format before, some format before and after and if you have issues, best doing it before and after flash) then reboot system. Once you see miui on screen or whatever logo you have, your good to go. It may take a long time first boot but as long as you see the logo, just wait.
My messenger is in the header and footer of the attached document if you need to message me or via this forums message service.
If there is anything else you need, please ask, nothing worse than being unsure. At least we can be unsure together! Good luck my friend.