Android Volley Ajax

I want to get a response from a URL that has to do ajax requests to get and update the page without refreshing it. My problem is when I want to receive its response with the volley library. In onResponse I just receive php code!!?

here is my code:

RequestQueue queue = Volley.newRequestQueue(getActivity());


        final String test= "MY URL";

        StringRequest stringRequest = new StringRequest(Request.Method.POST, test,
                new Response.Listener<String>() {
                    @Override
                    public void onResponse(String response) {
                        popup.dismiss();

                        Log.e("response", response );

                    }
                }, new Response.ErrorListener() {
            @Override
            public void onErrorResponse(VolleyError error) {
popup.dismiss();
            }
        });
        queue.add(stringRequest);

I tried with Request.Method.POST and Request.Method.GET but no difference.

NOTE: I only can see the response of this URL when I am using chrome and 'Allow-Control-Allow-Origin' extension is installed.