Xiaomi Mi 9 Cepheus SDM855 Flashing Without Authentication

Hi, how can i do flashing this model with UFI? Need without Auth.

ERROR: Only nop and sig tag can be recevied before authentication.

This Video Success:

https://www.youtube.com/watch?v=pP9gg2eYugk

i chekeched this video. i can not. i can't make it. how do you do?