The redirect URI in the request, http://congtruongit.com/forum/connected_account.php, does not match the ones authorized for the OAuth client. To update the authorized redirect URIs, visit: https://console.developers.google.com/apis/credentials/oauthclient/79378776643-u5api3ggnvg7g91nfbu1pkhvpnl8m3kb.apps.googleusercontent.com?project=79378776643