Here’s the guide that I wrote for iMore detailing the steps involved with upgrading the Logitech Circle 2 Camera to HomeKit Secure Video. Please note that this “conversion” process is listed as a beta by Logitech, and things can go awry. Also you will lose the ability to control and view your camera via the Circle app, and downgrades will require contacting Logitech’s support channels, so venture in at your own risk:
HomeKit Secure Video is finally here! The Logitech Circle 2 Camera is the first camera to support the privacy-focused feature, and although it may look scary, the upgrade process is quite easy. All you need is version 3.4.5 or later of the Logi Circle Security Camera app. Here’s how to get your camera updated in no time.