Hi! Sorry really late reply but you can find the fastboot Miui 13 here https://xiaomi.eu/community/threads/miui-13-stable-release.64441/
click on the "mirror" link and look for POCOF3, the latest Miui 13 version is 220.127.116.11
then just unzip all the folders and open up first_install_with_data_format with your phone plugged into your PC.
Although from my experience using both Miui 13 and 14 versions of xiaomi eu, 14 is may cleaner looking and smoother imo.