Problems with setting up on shared cpanel (Hostgator)

Codeigniter is now installed on the shared server. 

Code:

$routes->get('/', 'Home::index');   //default route

$routes->get('dash', 'Home::index');    //custom route

The default route works. But when I add any custom route and access it using <domain.com>/dash, it shows a 404 

Code:

Sorry, this page doesn't exist. Please check the URL or go back a page. 
404 Error. Page Not Found.