Apple has provided developers with the release candidates of iOS 15.7, iPadOS 15.7, macOS 12.6, and watchOS 9. A release candidate (RC), also known as “going silver”, is a beta version with potential to be a stable product.
Registered developers can download the betas via Apple’s developer portal. Or it can be downloaded over-the-air once the proper configuration profile has been installed from the Developer Center.