https://wccftech.com/ios-12-4-beta-3-beta-2-of-watchos-5-3-and-tvos-12-4-to-developers/

Today, Apple has seen fit to release the third beta of its upcoming iOS 12.4 firmware to developers. The new beta arrives two weeks after the company released iOS 12.3 to the general public. Alongside, the company has also released beta 2 of tvOS 12.4 and watchOS 5.3 to developers. If you’re a registered developer, you can install the latest builds right now. Let’s see what the company has added in its latest beta builds.

If you’re interested in installing iOS 12.4 beta 3 on your supported iPhone or iPad, it can be downloaded from the Apple Developer Center or via over-the-air. However, do take note that a proper configuration profile is installed from the Developer Center.