After today's keynote event that saw the unveiling of macOS 13 Ventura, the newest version of the Mac operating system, Apple has seeded the first beta of the new software to developers for testing purposes.
Registered developers can download the beta through the Apple Developer Center and once the appropriate profile is installed, betas will be available through the Software Update mechanism in System Preferences.
As with all new betas, Apple does not recommend installing macOS Ventura on a primary machine because it is early release software and could have bugs.
macOS Ventura is only available to registered developers right now, but later this summer, Apple will make a public version of the new beta available to give beta testers a chance to try the software before it sees an official launch this fall.
Article Link: Apple Seeds First Beta of macOS 13 Ventura to Developers