Hi i finished of configure the OAuth between Zammad and Gmail, i think and readed that this is for that my customers can create accounts in zammad with your own accounts of Gmail
But when i access to my system appear me the google option
The Redirect URI was in the error message and is passed to Google IDP over the URL attribute redirect_uri. Where did Zammad tell you this Redirect URI? Here would be the correct documentation for this, with the correct URI.
If you click on the user, do you see his email address listed in his profile? I believe that this is normal behaviour and it’s no problem because the user won’t be able to login with his username anyway.
You were in the wrong place in the settings. You were under Channels/Google, which is used for connecting Gmail Account. To set up OAuth, go to Settings/Security/Third-party Applications/Authentication via Google.