Issue on Accessing To Ajax Enqeued File to Pass to URL for Ajax Call

And it had no chance to work correctly.

When you use wp_localize_script like that:

wp_localize_script( $handle, $name, $data );

then the object called name is defined and data is it’s content. As you can see in this example from Codex.

So you can’t use ajaxurl in your JS file, because there is no such variable defined anywhere in your code.

The correct way is:

var request = $.ajax({
type: "POST",
url: ajax_custom.ajaxurl,