Code Igniter using Nginx on Ubuntu 16.04 can only access default_controller

I need help, I have tried to setup my Code Igniter Application with Nginx on Ubuntu 16.04 using PHP 5.6.30.

I can access the default_controller, but when I tried to access another controller even it's same with the default_controller but different route, it's always return 404.

Here is when I tried to access the default_controller :

Here is when I tried to access another controller / route :

Here is the config for Nginx :

Here is the config for Code Igniter :

Here is the route config on Code Igniter :

Please help if there something that I need to adjust or fix, Thank you.