Google People / API контактов Google не удалось

Я использую эту библиотеку: https://github.com/rapidwebltd/php-google-people-api

вот мой код:

<?php
require_once __DIR__ . '/vendor/autoload.php';

use RapidWeb\GooglePeopleAPI\GooglePeople;
use RapidWeb\GoogleOAuth2Handler\GoogleOAuth2Handler;

$clientId = '***-***.apps.googleusercontent.com';
$clientSecret = '***';
$refreshToken = '';
$scopes = ['https://www.googleapis.com/auth/userinfo.profile', 'https://www.googleapis.com/auth/contacts',
'https://www.googleapis.com/auth/contacts.readonly'];

$googleOAuth2Handler = new GoogleOAuth2Handler($clientId, $clientSecret, $scopes, $refreshToken);
$people = new GooglePeople($googleOAuth2Handler);

$contacts = $people->all();
print_r($contacts);

?>

и я получил следующую ошибку:

[fivesta1@sg21 googlecontacts]$ php create_contact.php

Fatal error: Uncaught exception 'Exception' with message '{
"error": {
"code": 401,
"message": "Request is missing required authentication credential. Expected OAuth 2 access token, login cookie or other valid authentication credential. See https://developers.google.com/identity/sign-in/web/devconsole-project.",
"status": "UNAUTHENTICATED"}
}
' in /home/fivesta1/public_html/googlecontacts/vendor/rapidwebltd/php-google-people-api/src/GooglePeople.php:63
Stack trace:
#0 /home/fivesta1/public_html/googlecontacts/create_contact.php(16): RapidWeb\GooglePeopleAPI\GooglePeople->all()
#1 {main}
thrown in /home/fivesta1/public_html/googlecontacts/vendor/rapidwebltd/php-google-people-api/src/GooglePeople.php on line 63

что я здесь пропустил? благодарю вас…