Что я делаю не так?

вот код python и из него надо сделать код c#

def send_p2p(api_access_token, to_qw, comment, sum_p2p):
s = requests.Session()
s.headers = {'content-type': 'application/json'}
s.headers['authorization'] = 'Bearer ' + api_access_token
s.headers['User-Agent'] = 'Android v3.2.0 MKT'
s.headers['Accept'] = 'application/json'
postjson = {"id":"","sum":{"amount":"","currency":""},"paymentMethod":{"type":"Account","accountId":"643"}, "comment":"'+comment+'","fields":{"account":""}}
postjson['id'] = str(int(time.time() * 1000))
postjson['sum']['amount'] = sum_p2p
postjson['sum']['currency'] = '643'
postjson['fields']['account'] = to_qw
res = s.post('https://edge.****.com/sinap/api/v2/terms/99/payments',json = postjson)
return res.json()

Код

def send_p2p(api_access_token, to_qw, comment, sum_p2p):

    s = requests.Session()

    s.headers = {'content-type': 'application/json'}

    s.headers['authorization'] = 'Bearer ' + api_access_token

    s.headers['User-Agent'] = 'Android v3.2.0 MKT'

    s.headers['Accept'] = 'application/json'

    postjson = {"id":"","sum":{"amount":"","currency":""},"paymentMethod":{"type":"Account","accountId":"643"}, "comment":"'+comment+'","fields":{"account":""}}

    postjson['id'] = str(int(time.time() * 1000))

    postjson['sum']['amount'] = sum_p2p

    postjson['sum']['currency'] = '643'

    postjson['fields']['account'] = to_qw

    res = s.post('https://edge.****.com/sinap/api/v2/terms/99/payments',json = postjson)

    return res.json()

вот код с#

private void Plata(string api_access_token, string to_qw, string sum_p2p, string num_volute)
{
Random rnd = new();
int value = rnd.Next(1, 1000);

string postjson = "{\"id\":\"\",\"sum\":{\"amount\":\"\",\"currency\":\"\"},\"paymentMethod\":{\"type\":\"Account\",\"accountId\":\"643\"}, \"comment\":\"None\",\"fields\":{\"account\":\"\"}}";
postjson = postjson.Replace("id", Convert.ToInt32(value * 1000).ToString());
postjson = postjson.Replace("amount", sum_p2p);
postjson = postjson.Replace("currency", num_volute);
postjson = postjson.Replace("account", to_qw);
var httpRequest = (HttpWebRequest)WebRequest.Create("https://edge.****.com/sinap/api/v2/terms/99/payments");
httpRequest.Method = "POST";
httpRequest.ContentType = "application/json";
httpRequest.Headers.Add("authorization", "Bearer " + api_access_token);
httpRequest.Headers.Add("user-agent", "Android v3.2.0 MKT");
using (var requestStream = httpRequest.GetRequestStream())
using (var writer = new StreamWriter(requestStream))
{
writer.Write(postjson);
}
using (var httpResponse = httpRequest.GetResponse())
using (var responseStream = httpResponse.GetResponseStream())
using (var reader = new StreamReader(responseStream))
{
string response = reader.ReadToEnd();
MessageBox.Show(response);
}
}

Код

private void Plata(string api_access_token, string to_qw, string sum_p2p, string num_volute)

        {

                Random rnd = new();

                int value = rnd.Next(1, 1000);

                

                string postjson = "{\"id\":\"\",\"sum\":{\"amount\":\"\",\"currency\":\"\"},\"paymentMethod\":{\"type\":\"Account\",\"accountId\":\"643\"}, \"comment\":\"None\",\"fields\":{\"account\":\"\"}}";

                postjson = postjson.Replace("id", Convert.ToInt32(value * 1000).ToString());

                postjson = postjson.Replace("amount", sum_p2p);

                postjson = postjson.Replace("currency", num_volute);

                postjson = postjson.Replace("account", to_qw);

                var httpRequest = (HttpWebRequest)WebRequest.Create("https://edge.****.com/sinap/api/v2/terms/99/payments");

                httpRequest.Method = "POST";

                httpRequest.ContentType = "application/json";

                httpRequest.Headers.Add("authorization", "Bearer " + api_access_token);

                httpRequest.Headers.Add("user-agent", "Android v3.2.0 MKT");

            using (var requestStream = httpRequest.GetRequestStream())

                using (var writer = new StreamWriter(requestStream))

                {

                    writer.Write(postjson);

                }

                using (var httpResponse = httpRequest.GetResponse())

                using (var responseStream = httpResponse.GetResponseStream())

                using (var reader = new StreamReader(responseStream))

                {

                    string response = reader.ReadToEnd();

                     MessageBox.Show(response);

                }

        }