Apple recently debuted the third beta software for watchOS, tvOS, and visionOS.
The three beta versions are for watchOS 11.5, tvOS 18.5, and visionOS 2.5. They came a week after the release of the second betas. The significant use case of these beta updates is for developers and those who want to test the software for bugs. The third beta is only accessible if you have a developer account and if there’s an Apple ID associated with that account. Updating to the third beta might be different for each device. Generally speaking, the device has to have a high battery charge or be connected to a power outlet, connected to an Apple device that has wi-fi.

From there, it’s a matter of going to System Settings and then Software Update, then tapping on the device you want. Most of the update is believed to be bug fixes and performance improvements.