Getting Authorization Required Error with youtube API call in CodeIgniter - php

Question

I am new to youtube data API, I want to let users from my website to upload directly to my youtube channel but I am a beginner in this aspect and this is what my client ask me to do.
I tried to use the example on https://developers.google.com/youtube/v3/code_samples/php but all that I get is:
Authorization Required You need to authorize access before proceeding.
I don't know anything concerning this topic. I am using the CodeIgniter PHP framework. This is the sample code I copied from Google Developer:
<?php
public function youtube(){
if (!file_exists(__DIR__ . '/../party/to/google/vendor/autoload.php')) {
throw new \Exception('please run "composer require google/apiclient:~2.0" in "' . __DIR__ .'"');
}
require_once __DIR__ . '/../party/to/google/vendor/autoload.php';
//session_start();
/*
* You can acquire an OAuth 2.0 client ID and client secret from the
* {{ Google Cloud Console }} <{{ https://cloud.google.com/console }}>
* For more information about using OAuth 2.0 to access Google APIs, please see:
* <https://developers.google.com/youtube/v3/guides/authentication>
* Please ensure that you have enabled the YouTube Data API for your project.
*/
$OAUTH2_CLIENT_ID = 'My Cleint Id';
$OAUTH2_CLIENT_SECRET = 'My Client Secret';
$client = new Google_Client();
$client->setClientId($OAUTH2_CLIENT_ID);
$client->setClientSecret($OAUTH2_CLIENT_SECRET);
$client->setScopes('https://www.googleapis.com/auth/youtube');
$redirect = filter_var('https:' . $_SERVER['HTTP_HOST'] . $_SERVER['PHP_SELF'],
FILTER_SANITIZE_URL);
$client->setRedirectUri($redirect);
// Define an object that will be used to make all API requests.
$youtube = new Google_Service_YouTube($client);
// Check if an auth token exists for the required scopes
$tokenSessionKey = 'token-' . $client->prepareScopes();
if (isset($_GET['code'])) {
if (strval($_SESSION['state']) !== strval($_GET['state'])) {
$data['messages'] = 'The session state did not match.';
}
$client->authenticate($_GET['code']);
$_SESSION[$tokenSessionKey] = $client->getAccessToken();
redirect($redirect,'refresh');
}
if (isset($_SESSION[$tokenSessionKey])) {
$client->setAccessToken($_SESSION[$tokenSessionKey]);
}
// Check to ensure that the access token was successfully acquired.
if ($client->getAccessToken()) {
$data['messages'] = '';
try{
// REPLACE this value with the path to the file you are uploading.
$videoPath = base_url('path/to/thevideo/video.mp4');
// Create a snippet with title, description, tags and category ID
// Create an asset resource and set its snippet metadata and type.
// This example sets the video's title, description, keyword tags, and
// video category.
$snippet = new Google_Service_YouTube_VideoSnippet();
$snippet->setTitle("Test title");
$snippet->setDescription("Test description");
$snippet->setTags(array("tag1", "tag2"));
// Numeric video category. See
// https://developers.google.com/youtube/v3/docs/videoCategories/list
$snippet->setCategoryId("22");
// Set the video's status to "public". Valid statuses are "public",
// "private" and "unlisted".
$status = new Google_Service_YouTube_VideoStatus();
$status->privacyStatus = "public";
// Associate the snippet and status objects with a new video resource.
$video = new Google_Service_YouTube_Video();
$video->setSnippet($snippet);
$video->setStatus($status);
// Specify the size of each chunk of data, in bytes. Set a higher value for
// reliable connection as fewer chunks lead to faster uploads. Set a lower
// value for better recovery on less reliable connections.
$chunkSizeBytes = 1 * 1024 * 1024;
// Setting the defer flag to true tells the client to return a request which can be called
// with ->execute(); instead of making the API call immediately.
$client->setDefer(true);
// Create a request for the API's videos.insert method to create and upload the video.
$insertRequest = $youtube->videos->insert("status,snippet", $video);
// Create a MediaFileUpload object for resumable uploads.
$media = new Google_Http_MediaFileUpload(
$client,
$insertRequest,
'video/*',
null,
true,
$chunkSizeBytes
);
$media->setFileSize(filesize($videoPath));
// Read the media file and upload it chunk by chunk.
$status = false;
$handle = fopen($videoPath, "rb");
while (!$status && !feof($handle)) {
$chunk = fread($handle, $chunkSizeBytes);
$status = $media->nextChunk($chunk);
}
fclose($handle);
// If you want to make other calls after the file upload, set setDefer back to false
$client->setDefer(false);
$data['messages'] .= "<h3>Video Uploaded</h3><ul>";
$data['messages'] .= sprintf('<li>%s (%s)</li>',
$status['snippet']['title'],
$status['id']);
$data['messages'] .= '</ul>';
} catch (Google_Service_Exception $e) {
$data['messages'] .= sprintf('<p>A service error occurred: <code>%s</code></p>',
htmlspecialchars($e->getMessage()));
} catch (Google_Exception $e) {
$data['messages'] .= sprintf('<p>An client error occurred: <code>%s</code></p>',
htmlspecialchars($e->getMessage()));
}
$_SESSION[$tokenSessionKey] = $client->getAccessToken();
} elseif ($OAUTH2_CLIENT_ID == 'REPLACE_ME') {
$data['messages'] = <<<END
<h3>Client Credentials Required</h3>
<p>
You need to set <code>\$OAUTH2_CLIENT_ID</code> and
<code>\$OAUTH2_CLIENT_ID</code> before proceeding.
<p>
END;
} else {
// If the user hasn't authorized the app, initiate the OAuth flow
$state = mt_rand();
$client->setState($state);
$_SESSION['state'] = $state;
$authUrl = $client->createAuthUrl();
$data['messages'] = <<<END
<h3>Authorization Required</h3>
<p>You need to authorize access before proceeding.<p>
END;
}
$this->template->load('public_layout','contents','youtube_testing_view',$data);
}
?>