public static void addPoints(String phone, int points, ResponseListener listener){
    try {
        phone = URLEncoder.encode(phone, "UTF-8");
        String url = "https://yourdomain.com/api/add_points.php?phone=" + phone + "&points=" + points;

        StringRequest request = new StringRequest(Request.Method.GET, url,
                response -> listener.onSuccess(response),
                error -> listener.onError(error.getMessage())
        );

        Volley.newRequestQueue(App.getContext()).add(request);

    } catch (UnsupportedEncodingException e){
        e.printStackTrace();
        listener.onError("Encoding Error");
    }
}