We can view the camera on our Google Nest Hello Doorbells when we are not at home, either on Wi-Fi or on cellular data (though response time may be slower on cellular data), and can enable the talk button, and we still get notices when we are not at home and the doorbell is rung. I assume the Google Nest Doorbell (Battery) can do the same, except that it has some limitations because it is battery-powered.
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