First, make sure that your computer meets the system requirements and give Hangouts access to your camera and mic.
Open Hangouts at hangouts.google.com or in Gmail.
At the top right, click Search .
Type a name or email address. ...
In the Hangout window that opens, click Video call .
Start a Hangout - Computer - Hangouts Help - Google Help
https://support.google.com/hangouts/answer/3115553?co...hl...Google