I need to help with routes problem.

I need to help with routes problem.

Below is a part of My Config/Routes.php file.

PHP Code:

$routes->setDefaultNamespace('MyTest\Controllers');
$routes->setDefaultController('Home');
$routes->setDefaultMethod('index');
$routes->setTranslateURIDashes(true);
$routes->set404Override('MyTest\Libraries\Errors::show404');
$routes->setAutoRoute(true); 


I need to use TranlateURIDashes. I hope that Router automatically route this.
for example, 'users/login-process' to 'users/login_process'.
but when I connect 'http://mytest/users/login-process', then just I could see 404 page not found error page.

So, Why? I don't understand this part..
Please, help me.

(Sorry, I'm not good at English..)