Verify your phone number when you first sign in When you sign in to Hangouts for the first time, you’ll be asked to verify your phone number. To edit your phone number, tap the number.
Confirm the number and tap Next.
Enter the verification code you receive in a text message.
After you see the “Verified” message, tap Done.
Verify your phone number when you’re already signed in
On your Android phone or tablet, open the Hangouts app Hangouts.
Tap Menu Menu and then Settings.
Select your Google Account.
Tap Verify phone number.