You can enable the camera on Google Hangouts on a computer or mobile device, though there are system requirements for the desktop version.

Security is easiest when you are the password: You don’t have to memorize complicated keywords, but simply hold your face up to the camera or your finger on a sensor — and you can access your computer ...

You can scan a QR code using the camera on your smartphone, tablet, or computer — however, you may need to download an app.