https://wccftech.com/download-ios-15-2-and-ipados-15-2-beta-3-now-available/

Developers can now download and install iOS 15.2 and iPadOS 15.2 beta 3 updates on their iPhone and iPad devices.

Alongside this new update, Apple has also seeded macOS Monterey 12.1 beta 3 to registered developers. If you have the previous beta running on your Mac, you can grab the latest update by going to System Preferences > Software Update.