How to send post request to remote server with parameters?

There is public website like Google, it receives an ID by user via Form and passes the related data back to user by button click. Website form example screenshot : public site link

Please help me how to implement it in my Android App, so that user could enter their ID and get result in App. my App screenshot

I have tried using Volley Library, but it retrieved only page source code. here is my Code.

private void sendPostRequest() {
    RequestQueue requestQueue = Volley.newRequestQueue(DawlatiKonkorResultActivity.this);
    String url = "http://kankorafghanistan.com/kankor-results/";
    StringRequest stringRequest = new StringRequest(Request.Method.POST, url, new Response.Listener<String>() {
        @Override
        public void onResponse(String response) {
            Log.d("success", "onResponse: success"+response);

        }
    }, new Response.ErrorListener() {
        @Override
        public void onErrorResponse(VolleyError error) {
            Log.d("failure", "onResponse: success"+error);

        }
    }){
        @Override
        protected Map<String, String> getParams(){
            Map<String,String> params = new HashMap<>();
            params.put("KankorID",editText.getText().toString());
            return params;
        }

        @Override
        public Map<String, String> getHeaders() throws AuthFailureError {
            Map<String,String> params=new HashMap<String, String>();
            params.put("Content-Type","application/x-www-form-urlencoded");
            return params;
        }
    };
    requestQueue.add(stringRequest);
}