Apple has released the third developer betas and public betas of iOS 14.4, iPadOS 14.4 , tvOS 14.4, and watchOS 7.3 to developers.
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.
If you’re not already signed up for the public beta program, you can do so here. The public beta program is free, but remember: beta software is unfinished software so use with care. The developer beta can be downloaded through the Apple Developer Center or the Software Update mechanism in the Mac App Store.