OAuth 2.0 refresh token is not available?

Question

I have a web based application which use Google OAuth2.0 as the login framework. It works nicely previously until yesterday. The applcation couldn't get the refresh token after the access token expired.

How can I remove the following error?

**PHP Fatal error**: Uncaught exception 'Google_AuthException' with message 'The OAuth 2.0 access token has expired, and a refresh token is not available.

Below is my code :

if (isset($_GET['code'])) {

  $client->authenticate($_GET['code']);
  $_SESSION['access_token'] = $client->getAccessToken();
  header('Location: ' . filter_var($redirect_uri, FILTER_SANITIZE_URL));
}


if (isset($_SESSION['access_token']) && $_SESSION['access_token']) {
  $client->setAccessToken($_SESSION['access_token']);
}

Answer 1

OAuth2访问令牌可以过期，您必须使用“刷新令牌”对其进行刷新-它始终与访问令牌一起使用。