https://wccftech.com/apple-releases-beta-3-of-ios-13-3-1-ipados-13-3-1-watchos-6-1-2-tvos-13-3-1-to-developers/

Today, Apple has seen fit to release the third developer beta of its upcoming iOS 13.3.1, iPadOS 13.3.1, watchOS 6.1.2, and tvOS 13.3.1 to developers for testing purposes. If you're a developer and want to try out the latest developer beta for yourself, you can install it on your compatible device right now. The beta builds arrive a week after the second developer beta was released. Let's dive in to see some more details on the beta build and what it has to offer.

Starting off with iOS 13.3.1 and iPadOS 13.3.1 beta 3, it can be downloaded from the Apple Developer Center or via the over-the-air mechanism. Take note that you need a proper configuration profile from the Apple Developer Center.