https://wccftech.com/download-ios-13-3-beta-1-ipados-13-1-for-iphone-ipad-now-available/

iOS 13.3 beta 1 and iPadOS 13.3 beta 1 for iPhone and iPad is now available for download. This is a developer-only release.

Apple has released a brand new beta of its software that powers the iPhone and iPad today. Dubbed iOS 13.3 beta 1 and iPadOS 13.3 beta 1, both are available directly from the Apple Developer Program website. Of course, this means that you must be registered developer with Apple in order to grab the pre-release software.