Getting error while calling post server to server outh token

API and Webhooks Meetings
1

getting this error when i make post call
response Id = 464, Status = WaitingForActivation, Method = “{null}”, Result = “{Not yet computed}” System.Threading.Tasks.Task<System.Net.Http.HttpResponseMessage>

here is the code
string ApiSecret = “”
var temp = Convert.ToBase64String(Encoding.ASCII.GetBytes(apicilentid + “:” + ApiSecret));

        //        //Post body content


        using (var client = new HttpClient())
        {
            client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Basic", temp);
            client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
            client.DefaultRequestHeaders.Host = "zoom.us";
           
            // POST content
            var content = new FormUrlEncodedContent(
                 new Dictionary<string, string> { { "grant_type", "account_credentials" },
             { "account_id", "" } });

            // make request

            var response =  client.PostAsync("https://zoom.us/oauth/token", content);

key account id client id are correct. it works in postman

2

Whats the error?