The firmware version is N98xFXXU3FVC5 (x being a different digit for different versions of the Note20 and Note20 Ultra phones) and should be also available in the Settings menu, under Software Update.
One UI 4.1 brings plenty of improvements alongside the obligatory bug fixes and security patches. There is now a Smart Calendar that reads dates from all messaging apps and allows for an easier input in the actual Calendar app.
Samsung Pay is another huge improvement. Galaxy Note20 users will now be able to store their drivers’ licenses, boarding passes, even car keys and movie tickets, making the Samsung app akin to Google Play and Apple Wallet. RAM Plus is a feature that pretty much every manufacturer is now enabling in their devices, and One UI 4.1 will offer you a choice of four options between 2GB and 8GB.