Download and install Google Duo from the app store
Open the app and sign in with your Google account or phone number
Allow access to contacts, microphone, and camera
Verify your phone number if prompted
Tap a contact to start a video or voice call
Use the search bar to find someone not shown in contacts
Tap the video call icon to start a video call
Tap the phone icon to start a voice call
During a call, use the on-screen controls to mute, switch camera, or end the call
Use the message option to send a video message if the person is unavailable
Adjust settings from the menu to manage notifications, blocked contacts, and call preferences
Keep the app updated for the latest features and security improvements