How I do it's usually in TWRP I wipe system data cache etc and then format data. Reboot to TWRP after formating data and then connect it with USB to a PC. It should show as removable storage. Copy the zips you want to flash and flash them from internal storage. If it doesn't show as a removable storage check in the mount section if MTP is enabled.getting ready to get arrow on a x3 ( just flashed my f2 last week )
big difference ; i could use sideload to get the rom zip on my f2 but that is missing from the x3 twrp.
is there another ( fastboot ) command to flash the zip ?
xiaomifastboottools can flash the twrp file but not the zip if i'm right...