How to load a model in Autoload file

How can I load a model in ...\app\Config\Autoload.php?

PHP Code:

namespace Config;

use CodeIgniter\Config\AutoloadConfig;

class Autoload extends AutoloadConfig {

    public function __construct() {
         //load here
         //i've tried,
         $my_model = new \App\Models\My_model();
         $my_model = model("App\Models\My_model");
    } 


Nothing is working.

What is the correct way? Looking for help.
Thanks in advance.