Apple has released the second public beta for iOS 13.4 and iPadOS 13.4. New features that are coming include a redesigned Mail toolbar, the return of iCloud folder sharing, a Shazam shortcut, new Animoji/Memoji stickers, new settings for Apple TV, and a new CarKey API for digital car keys.
iOS 13.4 Public Beta
As always, you can sign up for the public beta program here and install the beta profile. Then, go to Settings > General > Software Update to download the latest version.
If the rumors of an Apple event in March are true, we can expect to see the final release of iOS 13.4 at that time.