(403) Недостаточно прав для отправки электронной почты на gmail api

Я могу получить письмо с аутентификацией для чтения API Google. Я следовал за краткое руководство, и могу читать сообщения электронной почты после настройки клиента и связывания его с client_secret.json файл.

Пока что я работаю так:

<?php
require 'google-api-php-client/src/Google/autoload.php';

define('APPLICATION_NAME', 'Gmail API Quickstart');
define('CREDENTIALS_PATH', '~/.credentials/gmail-api-quickstart.json');
define('CLIENT_SECRET_PATH', 'client_secret.json');
define('SCOPES', implode(' ', array(
Google_Service_Gmail::GMAIL_READONLY)
));

/**
* Returns an authorized API client.
* @return Google_Client the authorized client object
*/
function getClient() {
$client = new Google_Client();
$client->setApplicationName(APPLICATION_NAME);
$client->setScopes(SCOPES);
$client->setAuthConfigFile(CLIENT_SECRET_PATH);
$client->setAccessType('offline');

// Load previously authorized credentials from a file.
$credentialsPath = expandHomeDirectory(CREDENTIALS_PATH);
if (file_exists($credentialsPath)) {
$accessToken = file_get_contents($credentialsPath);
} else {
// Request authorization from the user.
$authUrl = $client->createAuthUrl();
printf("Open the following link in your browser:\n%s\n", $authUrl);
print 'Enter verification code: ';
$authCode = trim(fgets(STDIN));

// Exchange authorization code for an access token.
$accessToken = $client->authenticate($authCode);

// Store the credentials to disk.
if(!file_exists(dirname($credentialsPath))) {
mkdir(dirname($credentialsPath), 0700, true);
}
file_put_contents($credentialsPath, $accessToken);
printf("Credentials saved to %s\n", $credentialsPath);
}
$client->setAccessToken($accessToken);

// Refresh the token if it's expired.
if ($client->isAccessTokenExpired()) {
$client->refreshToken($client->getRefreshToken());
file_put_contents($credentialsPath, $client->getAccessToken());
}
return $client;
}

/**
* Expands the home directory alias '~' to the full path.
* @param string $path the path to expand.
* @return string the expanded path.
*/
function expandHomeDirectory($path) {
$homeDirectory = getenv('HOME');
if (empty($homeDirectory)) {
$homeDirectory = getenv("HOMEDRIVE") . getenv("HOMEPATH");
}
return str_replace('~', realpath($homeDirectory), $path);
}

// Get the API client and construct the service object.
$client = getClient();
$service = new Google_Service_Gmail($client);

// Print the labels in the user's account.
$user = 'me';
//$results = $service->users_labels->listUsersLabels($user);

//$results = $service->users_messages->get('[email protected]', '14eadd821012b3ed');
$optParams['maxResults'] = 5;
$optParams['labelIds'] = 'INBOX';
$messages= $service->users_messages->listUsersMessages('me', $optParams);
$list = $messages->getMessages();
$messageId = $list[0]->getId();

$optParamsGet = [];
$optParamsGet['format'] = 'full';
$message = $service->users_messages->get('me', $messageId, $optParamsGet);
$messagePayload = $message->getPayload();
$headers = $message->getPayload()->getHeaders();
$part = $message->getPayload()->getParts();

$body = $part[0]['body'];
$rawData = $body->data;
$decodeMessage = base64_decode($rawData);

// THIS IS THE MESSAGE BODY I CAN GET

echo $decodeMessage;

Что меня удивляет, так это то, что, когда я пытаюсь отправить письмо, следуя инструкциям Google, я получаю сообщение об ошибке:

Error calling POST https://www.googleapis.com/gmail/v1/users/me/messages/send: (403) Insufficient Permission

Все, что я сделал, это добавил изменения внизу:

<?php
require 'google-api-php-client/src/Google/autoload.php';

define('APPLICATION_NAME', 'Gmail API Quickstart');
define('CREDENTIALS_PATH', '~/.credentials/gmail-api-quickstart.json');
define('CLIENT_SECRET_PATH', 'client_secret.json');
define('SCOPES', implode(' ', array(
Google_Service_Gmail::GMAIL_READONLY)
));

/**
* Returns an authorized API client.
* @return Google_Client the authorized client object
*/
function getClient() {
$client = new Google_Client();
$client->setApplicationName(APPLICATION_NAME);
$client->setScopes(SCOPES);
$client->setAuthConfigFile(CLIENT_SECRET_PATH);
$client->setAccessType('offline');

// Load previously authorized credentials from a file.
$credentialsPath = expandHomeDirectory(CREDENTIALS_PATH);
if (file_exists($credentialsPath)) {
$accessToken = file_get_contents($credentialsPath);
} else {
// Request authorization from the user.
$authUrl = $client->createAuthUrl();
printf("Open the following link in your browser:\n%s\n", $authUrl);
print 'Enter verification code: ';
$authCode = trim(fgets(STDIN));

// Exchange authorization code for an access token.
$accessToken = $client->authenticate($authCode);

// Store the credentials to disk.
if(!file_exists(dirname($credentialsPath))) {
mkdir(dirname($credentialsPath), 0700, true);
}
file_put_contents($credentialsPath, $accessToken);
printf("Credentials saved to %s\n", $credentialsPath);
}
$client->setAccessToken($accessToken);

// Refresh the token if it's expired.
if ($client->isAccessTokenExpired()) {
$client->refreshToken($client->getRefreshToken());
file_put_contents($credentialsPath, $client->getAccessToken());
}
return $client;
}

/**
* Expands the home directory alias '~' to the full path.
* @param string $path the path to expand.
* @return string the expanded path.
*/
function expandHomeDirectory($path) {
$homeDirectory = getenv('HOME');
if (empty($homeDirectory)) {
$homeDirectory = getenv("HOMEDRIVE") . getenv("HOMEPATH");
}
return str_replace('~', realpath($homeDirectory), $path);
}

// Get the API client and construct the service object.
$client = getClient();

//------------ MY CHANGES HERE ---------------

$service = new Google_Service_Gmail($client);

// Print the labels in the user's account.
$user = 'me';
//$results = $service->users_labels->listUsersLabels($user);

try {
$msg = new Google_Service_Gmail_Message();
$mime = rtrim(strtr(base64_encode("THIS IS A TEST MESSAGE"), '+/', '-_'), '=');
$msg->setRaw($mime);
$service->users_messages->send("me", $msg);
echo "OK";
} catch (Exception $ex) {
echo $ex->getMessage();

}

РЕДАКТИРОВАТЬ: я понял, что мой Google_Service_Gmail сфера была установлена READ_ONLY, Я пытался изменить это на MAIL_GOOGLE_COM за источник API на линии 34, но все равно получил ошибку.