https://wccftech.com/download-apple-releases-rc-versions-of-ios-14-5-and-ipados-14-5-macos-big-sur11-3-watchos-7-4-and-tvos-14-5/

Apple just announced a bunch of upgrades for the iMac, iPad Pro, Apple TV 4K, and much more, Other than this, Apple has also seen fit to release the RC version of iOS 14.5 and iPadOS 14.5, macOS Big Sur11.3, watchOS 7.4, and tvOS 14.5 to developers for testing purposes. The RC builds arrive a week after the previous beta was released.

If you are a developer, you can download the new RC build of iOS 14.5 and iPadOS 14.5, macOS Big Sur11.3, watchOS 7.4, and tvOS 14.5 on your compatible devices right now. Just make sure that you have installed a proper configuration profile from the Apple Developer Center.