No root access xiaomi mi 9t

Hi

I'm trying to install youtube revanced on my Xiaomi Mi 9T following the guidelines from https://www.reddit.com/r/revancedapp/comments/1pebuhd/simplest_way_to_get_the_official_revanced_youtube/ .
After patching and trying to install I get a pop up message saying:
'
No root access

The installation failed due to root access not being granted
Grant root access to ReVanced Manager and try again.
'

I have installed MicroG other than that I am not sure how to 'grant root access' to the revanced manager. Is it a phone specific issue? Rooting the Xiaomi itself is also quite difficult.