Apple has shipped the second developer betas of iOS 11.4.1, tvOS 11.4.1, and macOS High Sierra 10.13.6 for testing. The company has also posted watchOS 5 beta 1 for developers, after pulling last week’s build.
Registered developers can download them via Apple’s developer portal (https://developer.apple.com/account/#/welcome). Or they can be downloaded over-the-air once the proper configuration profile has been installed from the Developer Center.