How to set session expire on close

Hello eveybody,


do you know how to set:


$config['sess_expire_on_close'] = TRUE;


in version 4? My app\Config\App.php is:


public $sessionDriver            = 'CodeIgniter\Session\Handlers\FileHandler';
public $sessionCookieName        = 'ci_session';
public $sessionExpiration        = 7200;
public $sessionSavePath          = WRITEPATH . 'session';
public $sessionMatchIP           = false;
public $sessionTimeToUpdate      = 300;
public $sessionRegenerateDestroy = false;

and if I close the browser (not a single Tab, the browser) and then reopen it my old sessions are still there.

Thank you!