Google drive Upload returns - (403) Insufficient Permission - google-drive-api

Question

I am trying to upload files to google drive using service account, but i am getting error like
(403) Insufficient Permission error
Although fetching list of files from drive is working fine.
require_once 'google-api-php-client-master/src/Google/autoload.php';
require_once 'google-api-php-client-master/src/Google/Service.php';
session_start();
$client = new Google_Client();
$client->setAuthConfigFile('client_secrets.json');
$service_account_name = '251181790499-1en2vs6jjovga1egu15tphm1m7g44m60#developer.gserviceaccount.com';
$key_file_location = 'key.p12'; //key.p12
$key = file_get_contents($key_file_location);;
if (isset($_SESSION['access_token']) && $_SESSION['access_token']) {
$client->setAccessToken($_SESSION['access_token']);
//$client->addScope(Google_Service_Drive::DRIVE_METADATA_READONLY);
//$client->setScopes(array('https://www.googleapis.com/auth/drive'));
$cred = new Google_Auth_AssertionCredentials(
$service_account_name,
array('https://www.googleapis.com/auth/drive'),
$key);
$client->setAssertionCredentials($cred);
$client->setAccessType("offline");
$file = new Google_Service_Drive_DriveFile();
$file->setTitle(uniqid().'.jpg');
$file->setDescription('A test document');
$file->setMimeType('image/jpeg');
$data = file_get_contents('a.jpg');
$service = new Google_Service_Drive($client);
$createdFile = $service->files->insert($file, array(
'data' => $data,
'mimeType' => 'image/jpeg',
'uploadType' => 'multipart'
));
print_r($createdFile);
}
else
{
$redirect_uri = 'http://' . $_SERVER['HTTP_HOST'] . '/googledrive/oauth2callback.php';
header('Location: ' . filter_var($redirect_uri, FILTER_SANITIZE_URL));
}
I have reviewed similar questions in forum and tried suggestions but nothing seems to work.
Is there anything wrong with code?

Answer 1

Change your Google Drive Scope to
Google_Service_Drive::DRIVE
in PHP
$client->addScope(Google_Service_Drive::DRIVE);