I have an app , QR scanner I can't even open it. and in active monitor panel it shows that my pc uses idle process 93%

Perhaps that app doesn't work with Monterey.

There are quite a few on the Mac App Store, but none by that name. Where did you get it?

For the other half of the question, I don't know what you are describing. That might have been a good use of a screenshot. However, what actual problem are you having with your Mac that made you notice the "idle process" usage?