Welcome to the Google Duo Help CenterGet started with Google DuoSet up Google DuoTips for using Google DuoFind and invite contactsMake a callStart a call with anyone, anywhereTurn Knock Knock on or offBlock numbers from calling you on Google DuoChange settingsLimit mobile data usageSet phone to vibrate for callsDisconnect your phone number from Google DuoTroubleshoot issuesHow to send feedbackCan’t verify phone numberCan't find or sync contactsFix video call connection