What version of the Xiaomi Stable ROM do you currently have?
If this is 188.8.131.52 or 184.108.40.206, then if you have twrp installed on your device, then simply install xiaomi.eu ROM wia twrp. (8.7.19 (or 26)).
(Do not recomend )
If your version of Stable ROM is higher than 220.127.116.11 Try This. (google...
Install From Sdcard or Flash via OTG.
But you can format the Data in TWRP, reboot the smartphone to system, make the initial setup, after copying the firmware file into the smartphone's memory, reboot into the twrp recovery and flash it from the internal memory.
How You can see bootloader status:
Through the PC on Windows: first the phone should be booted in fastboot mode (power button + volume down key) - to do this, connect your gadget to the computer - on the PC, press Win + R - enter "cmd" - in the command line write " adb "- press Enter - enter"...
3. Twrp.bat must be started from PC
4. You can not flash ROM from internal storage, because section DATA will be encrypted and don't available in TWRP. Put ROM to SD Card.
5. After you start the TWRP.bat, the recovery will start in the smartphone...
Redmi 6 Pro. Camera crash in portrait mode.
Periodically the reading mode does not work.
If you reboot after a camera failure, the reading mode is restored, but it's worth to go into the camera - again the camera drops with an error and then the read mode does not work.