Google Admin 403 Error with PHP - google-admin-sdk

Question

I have been searching and trying many different solutions to this error that I have found not only this site but others as well.
Currently I am trying to just get a list of users or a specific user details based on parameters set. In the long run I would like to create and modify users and groups.
I have images but am new to posting to this site and I am unable to publish them here. I can confirm the following:
I have enabled API for the domain
api_studentportal(at)domain.com is a super admin
The Admin SDK is enabled under the developers console
Under 'Manage API client access' I have added '474470900273-asrfjsg0m0ucsfadeit456sg518l1bqa.apps.googleusercontent.com' to 'admin.directory.group' and 'admin.directory.user'
My Code:
date_default_timezone_set('America/Los_Angeles');
session_start();
set_include_path(get_include_path() . PATH_SEPARATOR . 'google/composer/src');
require 'composer/vendor/autoload.php';
$keychain = json_decode(file_get_contents('Google.json'), true);
$service_account_name = $keychain['client_email']; //474470900273-asrfjsg0m0ucsfadeit456sg518l1bqa#developer.gserviceaccount.com
$private_key = $keychain['private_key'];
$client = new Google_Client();
$client->setApplicationName("SAMPLE");
$service = new Google_Service_Directory($client);
if (isset($_SESSION['service_token'])) {
$client->setAccessToken($_SESSION['service_token']);
}
$cred = new Google_Auth_AssertionCredentials(
$service_account_name,
array('https://www.googleapis.com/auth/admin.directory.user', 'https://www.googleapis.com/auth/admin.directory.group'),
$private_key,
'notasecret',
'http://oauth.net/grant_type/jwt/1.0/bearer',
'api_studentportal#domain.com'
);
$client->setAssertionCredentials($cred);
if($client->getAuth()->isAccessTokenExpired()) {
$client->getAuth()->refreshTokenWithAssertion($cred);
}
$_SESSION['service_token'] = $client->getAccessToken();
$service = new Google_Service_Directory($client);
// Print the first 10 users in the domain.
$optParams = array(
'domain' => 'domain.com',
'maxResults' => 10,
'orderBy' => 'familyName',
'viewType' => 'domain_public',
);
$results = $service->users->listUsers($optParams);
And then I get the following PHP error:
Fatal error: Uncaught exception 'Google_Service_Exception' with message 'Error calling GET https://www.googleapis.com/admin/directory/v1/users?domain=domain.com&maxResults=10&orderBy=familyName&viewType=domain_public: (403) Not Authorized to access this resource/api' in google/composer/src/Google/Http/REST.php:110 Stack trace: #0 google/composer/src/Google/Http/REST.php(62): Google_Http_REST::decodeHttpResponse(Object(Google_Http_Request), Object(Google_Client)) #1 [internal function]: Google_Http_REST::doExecute(Object(Google_Client), Object(Google_Http_Request)) #2 google/composer/src/Google/Task/Runner.php(174): call_user_func_array(Array, Array) #3 google/composer/src/Google/Http/REST.php(46): Google_Task_Runner->run() #4 google/composer/src/Google/Client.php(593): Google_Http_REST::execute(Object(Google_Client), Object(Google_Http_Request)) #5 google/composer in google/composer/src/Google/Http/REST.php on line 110

Answer 1

It seems as if it was just the viewType optParam defined. 'viewType' => 'domain_public' is invalid. Once that was removed the query worked.