Checking in your direct report's performance before every 1-on-1 meeting helps to keep track of their performance and discuss any performance-related concerns in 1-on-1s.
Open your upcoming 1-on-1 with your direct report. A pop up will ask you to rate your direct report's performance.
Alternatively, you can also give a performance rating later. Scroll down to Private Notes and click on 'Rate Performance'.
The performance ratings are only visible to you. Your direct employes can't view the rating. You can also access performance check-in through the reminder mail sent to you a day before your 1-on-1 meeting.
This is how you can rate your direct report's performance: