Apple is in the process of testing a minor update to all of its major platforms, including seeding beta versions of the software ahead of the public launch.
Apple has officially seeded the fifth developer beta of upcoming updates for iOS and macOS High Sierra. Each of the updates appear to be minor in scope, new software designed to address any issues that were discovered in previous version of the platforms. At the time of publication, it is not known what, if anything, is new for the end user in the new versions of the platforms, but if anything is discovered we will update this post accordingly.
It is possible that Apple will seed corresponding public betas of the pre-release software ahead of a public launch as well, which may arrive next week.
To update to iOS 11.4.1, you must be a registered developer. If you have the proper configuration profiles installed on your test devices, the software can be downloaded and installed as an over-the-air update by navigating to Settings –> General –> Software Update and then following the onscreen instructions.
To update to macOS High Sierra 10.13.6, the proper configuration profiles must be installed. Once they are, the new software can be downloaded and installed from the Mac App Store by selecting the Updates tab and choosing to install the new software.
The new betas are available now to download and install for registered developers.