In both bat's comments you write "Should not be used in case of switching from any custom ROM with TWRP to ROM based on ORIGINAL MIUI dev ROM." Well I have, in theory, TWRP and want to switch to stock recovery.
So which bat should I use?
I didnt delete "fastboot oem verified" i missed your post here.
tried "fastboot oem unlock" but i get something like unable to unlock (var locked=yes)
done data format, I guess it leaves me with flashing original recovery. Which file is it? boot.img, bootloader.img or something else?