After starting the Android 11-based One UI 3.0 beta program for the users in the US, Korea, and Germany, the company is now starting the beta program for the Exynos-powered Galaxy S20 users in India. The company may also start the beta program in the UK, Poland, and China.
If you are in India, you can register via the Samsung Members app on your Galaxy S20, S20+, or S20 Ultra. After the successful registration, you can expect an update notification on your phone.
If you want to check for the latest software update, just head to the device Settings and tap on the Software update menu.
source - rprna.com