Configure apache module on ubuntu 16.04

I created a hello world module on ubuntu 16.04

#include <httpd.h>
#include <http_protocol.h>
#include <http_config.h>

static int helloworld_handler(request_rec* r)
{
    if (!r->handler || strcmp(r->handler, "helloworld"))
        return DECLINED;

    if (r->method_number != M_GET)
        return HTTP_METHOD_NOT_ALLOWED;

    ap_set_content_type(r, "text/html");
    ap_rprintf(r, "Hello, world!");
    return OK;
}

static void register_hooks(apr_pool_t* pool)
{
    ap_hook_handler(helloworld_handler, NULL, NULL, APR_HOOK_MIDDLE);
}

module AP_MODULE_DECLARE_DATA helloworld_module = {
    STANDARD20_MODULE_STUFF,
    NULL,
    NULL,
    NULL,
    NULL,
    NULL,
    register_hooks
};

      

        
        
        
      

    

compile it with this command:

apxs -iac mod_helloworld.c

      

        
        
        
      

    

I see a module running it

apache2ctl -M

      

        
        
        
      

    

and

a2enmod

      

        
        
        
      

    

if i run

sudo a2enmod helloworld

      

        
        
        
      

    

I see that this module is already enabled

I also added this helloworld.conf to the available mods folder

<Location /helloworld>
    SetHandler helloworld_handler
</Location>

      

        
        
        
      

    

and the helloworld.load file contains

LoadModule helloworld_module  /usr/lib/apache2/modules/mod_helloworld.so

      

        
        
        
      

    

How do I configure it to view the output in a browser like

http: // localhost / helloworld

mod_helloworld.so is located under / usr / lib / apache2 / modules

if I root@ubuntu:/var/log/apache2# tail -f access.log

I get this

127.0.0.1 - - [03/Aug/2017:03:18:14 -0700] "GET /helloworld HTTP/1.1" 404 500 "-" "Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:54.0) Gecko/20100101 Firefox/54.0"

      

        
        
        
      

    

How to solve it?