Method PostPEAssocDetail

using System.Net;
using Newtonsoft.Json.Linq;

public void MethodName(parms){
    string uri = "https://fusion.centralsquare.com/FusionOSServices/v2/ONESolution/PersonEntity/PEAssocDetail";
    string data = 
    @"[{
          ""peId"": ""104202"",
          ""assocCd"": ""1042RECP"",
          ""codeVal"": ""02"",
          ""codeDesc"": ""aerthf"",
          ""uniqueKey"": ""a5a70f0e-457f-11d9-825d-00306e2c5246"",
          ""codeNum"": ""0.00000"",
          ""codeDt"": """",
          ""createWhen"": """",
          ""createWho"": """",
          ""updateWhen"": ""10/2/2020 8:10:35 PM"",
          ""updateWho"": ""RESTAPI""
    }]";

    using (WebClient wc = new WebClient())
    {
        wc.Headers.Add("Content-Type", "application/json");
        // Replace "ID" with supplied AppID
        wc.Headers.Set("X-APPID", "ID");
        // Replace "KEY" with supplied AppKey
        wc.Headers.Set("X-APPKEY", "KEY");

        string result = wc.UploadString(uri, "POST", data);

        JObject response;
        if (!string.IsNullOrWhiteSpace(result))
             response = JObject.Parse(result);
    }
}