$header = @{

         Host: "#########";

         Authorization: "Basic ####################";

       }


$body = @{

        sourceName = "Anything here";

        sourceId = "Anything here ";

        sourceIP = "##.##.##.###";

        sourcePort = ####;

        datetime = "###############";

        payload = {

           monitors = [

                      "REST response time",

                      "Authentication failures"

                ]
           }

        }

  $Js = $body | ConvertTo-Json;

  $response = Invoke-RestMethod -Method PUT -Headers $headers -Uri http://$ipAddr/reader/monitors -Body $Js;