Apple has released the second developer beta and second public beta of macOS 11.5. 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.
As for the public beta of macOS 11.5, it’savailable on Apple’s Beta Software Program website. Just remember that beta software, so proceed with care.
Apple does public betas in order to increase the size of the pool of testers. The tech giant recommends keeping back-ups of your files before installing a public beta.