Beta builds are available to developers over the air on the devices with the proper configuration installed. Developers can also download the new betas from the Apple Developer Center.
Apple last Monday released the first public beta versions of its four upcoming new operating systems, macOS Catalina, iOS 13, iPadOS, and tvOS 13.
Apple is also running a beta testing round for updates to their currently available operating systems. iOS 12.4, tvOS 12.4, watchOS 5.3, and macOS 10.14.6 are currently in their fifth round of testing.
As usual, MacTrast and Apple both warn users to not install any betas on your daily driver iPhone, iPad, Apple TV, Apple Watch or Mac computer, instead only install it on a device set aside for testing purposes.