Method GetPOUsedAmount

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

public void MethodName(parms){

    string primaryKeyword = "P17939"; // Replace with actual PO number
    string uri = "https://fusion.superion.com/FusionOSServices/v0/ONESolution/OnBase/POUsedAmount?primaryKeyword=" + primaryKeyword;

    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.DownloadString(uri);
        var response = JObject.Parse(result);
        var records = (JContainer)response["values"];

        foreach (var record in records)
        {
            decimal poSpent = (decimal)record["poSpent"];
        }
    }
}

                        
            {
              "values": [
                {
                  "poSpent": 550.50
                }
              ],
              "count": 1
            }