Call Action Method on button click ASP.NET MVC

I am trying to get user input in button click. When user insert number and press Check, it needs to return xml data type. So in my controller I create function which will return a data for passing ID

[ResponseType(typeof(AKONTA))]
        public IHttpActionResult GetAKONTA(string id)
        {
            AKONTA aKONTA = db.AKONTAS.Find(id);
            if (aKONTA == null)
            {
                return BadRequest("Ne postoji A_KONTO pod tim rednim brojem");
            }

            return Ok(aKONTA);
        }

And In my View I have following

<br /><br />
<form>
    <div class="form-group">
        <label>A_KONTO</label>
        <input type="text" class="form-control" aria-describedby="AKONTO BROJ" placeholder="Unesite broj AKONOTO">
    </div>

    <div class="form-group">
        <a asp-action="Index" class="btn btn-primary" id="aKonto" action="@Url.Action("GetAKONTA", "Akontas")">Provjeri</a>
    </div>
</form>

And I want to create in btn click when user pass ID it needs to return XML data format.

SO far I create a JS function, but I don't know JavaScript and don't know the logic how to pass Controller Action Result to JS.

  <script>
        $(document).ready(function () {
            $('#aKonto').click(function () {
                document.getElementById("aKonto").onclick = function () {GetAKONTA()};;
            });
        });
    </script>

If someone can help me I would be very thankful. Cheers !

UPDATE

function aKontoSubmit() {
            $.ajax({
                type: "GET",
                url: 'api/Akontas',
                //data: { id: id },
                dataType: "xml",
                success: function (result) {
                    // action to do after form submit
                },
                error: function () {
                    alert("Ne postoji AKONTO pod tim rednim brojem");
                }

            });
        }

**routeConfig**

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Mvc;
using System.Web.Routing;

namespace AkontasWebApi
{
    public class RouteConfig
    {
        public static void RegisterRoutes(RouteCollection routes)
        {
            routes.IgnoreRoute("{resource}.axd/{*pathInfo}");


            routes.MapRoute(
                name: "Default",
                url: "{controller}/{action}/{id}",
                defaults: new { controller = "Home", action = "Index", id = UrlParameter.Optional }
            );
        }
    }
}