Do you have to put the TWRP.img in your phone before proceeding with the steps? I can't seem to detect my mi10t pro storage after plugging in to my computer, and it shows nothing in Internal Storage /sdcard
Edit: For some reason it did not prompt me to decrypt user in recovery, and I was unable to mount and decrypt my data using advanced password, it will just show invalid password. After changing to 4 digit pin, I went back to recovery, and it prompt me to key in the pin to decrypt. After this, I was able to change back to my advance password, and it will prompt when entering recovery and decrypt successfully.