ajax request 404 error

See: https://codeigniter.com/user_guide/general/ajax.html

On your ajax part you would add headers to support this.

edit:
It also depends on what the URL in your routes is accepting, if for example you use the get() method.
Personally i would use (and i'm using this) the url_to() for this part.

> routes - https://codeigniter.com/user_guide/incom...al-options
> url_to() - https://codeigniter.com/user_guide/helpe...tml#url_to