谷歌API/日历:can'；我找不到使用谷歌api的方法

我正试图使用谷歌日历api及其php客户端库来创建一个php函数，该函数使用我通过参数赋予它的变量来添加事件。

但是文档似乎已经过时了，我找不到一个好的教程来帮助我

<?php
require_once 'google-api-php-client/autoload.php';
session_start();
//require_once 'google-api-php-client/src/Google/Client.php';
//require_once 'google-api-php-client/src/Google/Service/Calendar.php';
$client = new Google_Client();
$client->setApplicationName("test");
$client->setClientId("xxxx.apps.googleusercontent.com");
$client->setClientSecret("xxxx");
$client->setRedirectUri("http://localhost/");
$client->setDeveloperKey("xxxx");
$service = new Google_Service_Calendar($client);
$event = new Google_Service_Calendar_Event();
$event->setSummary('Appointment');
$event->setLocation('Somewhere');
$start = new Google_Service_Calendar_EventDateTime();
$start->setDateTime('2014-10-16T10:00:00.000-07:00');
$event->setStart($start);
$end = new Google_Service_Calendar_EventDateTime();
$end->setDateTime('2014-10-16T10:25:00.000-07:00');
$event->setEnd($end);

/*$attendee1 = new EventAttendee();
$attendee1->setEmail('attendeeEmail');
$attendees = array($attendee1,
// ...
);
$event->attendees = $attendees;*/
$createdEvent = $service->events->insert('primary', $event);
echo $createdEvent->getId();
?>

我的浏览器告诉我：

Fatal error: Uncaught exception 'Google_Service_Exception' with message 'Error calling POST https://www.googleapis.com/calendar/v3/calendars/primary/events?key=xxxx: (401) Login Required' in C:'wamp'www'cnsi'google-api-php-client'src'Google'Http'REST.php on line 76

有人能帮帮我吗？