Surprise! Two weeks after releasing iOS 13.4, Apple has another iOS update ready to roll.
iOS 13.4.1 and iPadOS 13.4.1 are now available for download. As you might expect from an x.x.1 update, this is a fairly minor release, bringing a fix for a bug that'd prevent devices on iOS 13.4 from participating in FaceTime calls with devices running older iOS and OS X versions.
Here's Apple's changelog for iOS 13.4.1:
If you've got an iOS 13-capable iPhone or iPad, you can grab this update by going into Settings > General > Software Update.