https://wccftech.com/beta-1-of-macos-12-4-watchos-8-6-tvos-15-5-released/

You can now go ahead and download beta 1 of macOS 12.4 Monterey, watchOS 8.6 and tvOS 15.5 on your Mac, Apple Watch and Apple TV, respectively.

Alongside these updates, Apple has also released iOS 15.5 and iPadOS 15.5 beta 1. If you're interested in that instead, then make sure you check out the following: