I'm trying to root my xiami Redmi 9T, and to do that I have to root it from twrp recovery. I've unlocked the phone(waited 7 days), got twrp from here. What I have read online I have to boot my phone directly from fastboot because if I boot it normaly the xiaomi recovery will overwrite twrp and MIUI will force it go back to original recovery(from which you can't root the phone). But I can't boot it from fastboot because I get this unknown error I don't know how to fix. Fastboot boot twrp.img does not work as you can see.
I managed to solve the issue. First I tried to boot it up by pressing + sound button while typing "fastboot reboot" in cmd at the same time, that did not work, I would just got a black screen. Turns out the twrp was not good, so I downloaded a different one and it worked out. The one I took was from here called "twrp-3.5.2_10-3-lime-brigudav.img"