i just want practice rank map in normal。
Create a 2nd account for steam and share the game via family sharing with yourself.
You can have multiple accounts that way and only buy the game once.
Then you can practice ranked on 2nd account.
When I still played aoe4, I usually played 1 match of 1v1 ranked on my 2nd acc as a warmup, when it was my 1st match of the day.
Then I played on my main.