CodeIgniter Simple and Secure Twig

Hello,
In doc it is written :
You can override the default configuration:

PHP Code:

$config = [
   'paths' => ['/path/to/twig/templates', VIEWPATH],
   'cache' => '/path/to/twig/cache',
];
$this->load->library('twig', $config); 


That is clear, but I load twig in autoload file, as :

PHP Code:

$autoload['libraries'] = array('ion_auth', 'twig' ); 


How to overwrite config in this case?

  Thanks!