For credentials, I have created an developer account on https://console.developers.google.com, I have created a project and then i have created credentials from API Manager. I use "google/apiclient": "1.1.*" package. I think it is a problem with credentials.
$OAUTH2_CLIENT_ID = 'XXXXX-rvm1l9b1nvht9je1ic0bbe05ab5gvhbg.apps.googleusercontent.com';
$OAUTH2_CLIENT_SECRET = 'XXXXXXP90L_DLD3Nrc_rT4zGD';
$client = new Google_Client();
$client->setClientId($OAUTH2_CLIENT_ID);
$client->setClientSecret($OAUTH2_CLIENT_SECRET);
$client->setScopes('https://www.googleapis.com/auth/youtube');
$redirect = url('/');
$client->setRedirectUri($redirect);
$token = $client->getAccessToken();
dd($token);