Unable to turn on Private on iMac running Big Sur 11.6.8 and Safari 15.6.1

I have iCloud +.

According to this article (Use iCloud Private Relay on Mac - Apple Support, with my current software, I should be able to turn on Private Relay by using the Beta version. However that option does not show up when I go to Mac, choose Apple menu  > System Preferences, click Apple ID , then select iCloud in the sidebar.

Am I missing something?

— macgroupie

Is there some place I can load the Private relay.