Time machine problem

[surfbug]

I've 2020 imac. How do I go back on the time machine 1 week ago. Do I use command r or something else?

 

[HDFan]

How do I go back on the time machine 1 week ago.

Not sure I understand your question. You want to restore something from Time Machine? As you have checked "Show Time Machine in menu bar" checked, you should see the icon there:

(I have a backup in progress. Icon is different when backup is not running). Click on "Enter Time Machine"