Well, if you weren’t one of those who got the update and want to give Android 12 and One UI 4.0 a try, you can participate in the One UI 4.0 beta program by tapping on the One UI Beta Program banner in the Samsung Members app. But do note that it’s only open to the unlocked Galaxy S20, S20+, and S20 Ultra units.
Once you are enrolled, you can navigate to the Settings > Software update menu on your device to download the first One UI 4.0 beta update. This procedure applies to the Galaxy Note20 series as well.
However, it’s worth noting that beta firmware isn’t as stable as the final builds, so it’s best avoided on primary devices.