get_payments method doesn't display data

Question

I am trying to run get_payments method of wallet rpc.

Got this error

Warning: Binary output can mess up your terminal. Use "--output -" to tell Warning: curl to output it to your terminal anyway, or consider "--output Warning: " to save to a file.

Then I tried to run it from .net like this:

var str = "{\"jsonrpc\":\"2.0\",\"id\":\"0\",\"method\":\"get_payments\",\"params\":{\"payment_id\":\"60900e5603bf96e3\"}}";

        var httpWebRequest = (HttpWebRequest) WebRequest.Create ("http://127.0.0.1:18082/json");
        httpWebRequest.ContentType = "application/json";
        httpWebRequest.Method = "POST";

        using (var streamWriter = new StreamWriter (httpWebRequest.GetRequestStream ())) {
            string json = str;

            streamWriter.Write (json);
        }
        string result;
        var httpResponse = (HttpWebResponse) httpWebRequest.GetResponse ();
        using (var streamReader = new StreamReader (httpResponse.GetResponseStream ())) {
            result = streamReader.ReadToEnd ();
            System.Console.WriteLine (result);

        }

        //string final = JsonConvert.DeserializeObject(result, new JsonSerializerSettings { Formatting = Formatting.Indented });
        var x = result.ToString ();
        string resultfinal = x.Replace ("\\n", string.Empty).Replace ("\\", "");

        string j = JsonConvert.SerializeObject (result);

        return resultfinal;

And got Internal Server Error.

WebException: The operation has timed out.

I have payment Id, how do I get payment information?