Google Drive Rest API authentication issue after entering id, secret, and key - php

Question

I want to use Google Drive rest Api to list the files on the drive. But there is an authentication problem.
I enter the Client Id , Client secret, and Api key but it's not working. I use the library.
My code is as follows:
<?php
function get_gdrive_file_list($operation) {
include(VIS_PATH_PLUGINS.'gmail_login/src/Google_Client.php');
include(VIS_PATH_PLUGINS.'gmail_login/src/contrib/Google_DriveService.php');
$client = new Google_Client();
$client->setClientId('****************************');
$client->setClientSecret('**********************');
$client->setRedirectUri('**********************');
$client->setDeveloperKey('*********************');
$cal = new Google_DriveService($client);
if (isset($_SESSION['code'])) {
$client->authenticate($_SESSION['code']);
$_SESSION['token'] = $client->getAccessToken();
unset($_SESSION['code']);
}
if (isset($_SESSION['token'])) {
$client->setAccessToken($_SESSION['token']);
}
if ($client->getAccessToken()) {
$calList = $cal->files->listFiles();
echo "Result : ";echo "<pre>";print_r($calList);echo "</pre>";echo "<br>";
}
} ?>