https://wccftech.com/apple-seeds-second-public-beta-of-macos-monterey/

Today, Apple has seen fit to release beta 3 of its upcoming macOS 12 Monterey to the public. The new beta build is oriented towards the general public so everyone can give it a go. The new beta arrives two weeks after the first beta was seeded to the public. If you are enrolled in Apple's public beta program, you can download it right now on your compatible Macs.

If you are interested and enrolled in Apple's public beta program, you can install the latest macOS 12 Monterey beta 3 on your compatible Mac from the Software Update section in System Preferences. Make sure that you have installed the proper configuration profile from the Apple beta software website.