使用下面的代码我可以获得访问和刷新令牌：

private const SCOPE                 = 'https://www.googleapis.com/auth/adwords';
private const AUTHORIZATION_URI     = 'https://accounts.google.com/o/oauth2/v2/auth';
private const OAUTH2_CALLBACK_PATH  = '';
private const REDIRECT_URL          = 'http://localhost:3000/google/google-ads/confirmed';

$code           = $request->input('code');
$scope          = $request->input('scope');
$state          = $request->input('state');
$project_token  = $request->input('project_token');
$project_name   = $request->input('project_name');
$account_name   = $request->input('account_name');
$account_id     = $request->input('account_id');

$clientId       = 'my-client-id--kh3el.apps.googleusercontent.com';
$clientSecret   = 'my-clicent-secret4cCm';
$redirectUrl    = self::REDIRECT_URL;

$oauth2 = new OAuth2(
    [
        'clientId'              => $clientId,
        'clientSecret'          => $clientSecret,
        'authorizationUri'      => self::AUTHORIZATION_URI,
        'redirectUri'           => $redirectUrl . self::OAUTH2_CALLBACK_PATH,
        'tokenCredentialUri'    => CredentialsLoader::TOKEN_CREDENTIAL_URI,
        'scope'                 => self::SCOPE,
        // Create a 'state' token to prevent request forgery. See
        // https://developers.google.com/identity/protocols/OpenIDConnect#createxsrftoken
        // for details.
        'state' => sha1(openssl_random_pseudo_bytes(1024))
    ]
);

// Set the authorization code and fetch refresh and access tokens.
$oauth2->setCode($code);
$authToken = $oauth2->fetchAuthToken();

$refreshToken   = isset( $authToken['refresh_token'] ) ? $authToken['refresh_token'] : '';
$accessToken    = $oauth2->getAccessToken();

现在怎么才能得到邮箱地址？有办法吗？