Not exactly the ask, but a user friendly alternative is HomeKit cameras with a HomePod mini as a hub for local processing. Some can be paired without any app, and once paired you can block internet access at the router level. You can access them through the local network. If you trust apples e2e encryption you can access remotely through the homepod.
I was going to say the same. My Logitech Circle has no app, even if I wanted one. All setup is in the Home app and it works even if my home WiFi is not connected to the wider internet.
