$client_id = 'xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx'; // Client ID
$client_secret = 'XXXXXXXXXXXXXXXXXXXXXXX'; // Client secret
$redirect_uri = 'https://site.ru/social_login_callback/google.php'; // Redirect URI



$url = 'https://accounts.google.com/o/oauth2/auth';

$params = array(
    'redirect_uri'  => $redirect_uri,
    'response_type' => 'code',
    'client_id'     => $client_id,
    'scope'         => 'https://www.googleapis.com/auth/userinfo.email https://www.googleapis.com/auth/userinfo.profile'
);


header('Location: '. $url . '?' . urldecode(http_build_query($params)) ); exit();