access API on imagoxt - vb.net

Question

i must download some information from API exposed by a server, but whit information in my hand i'm very in difficult.
my code :
Dim request As HttpWebRequest
Dim response As HttpWebResponse = Nothing
Dim reader As StreamReader
Dim address As Uri
Dim data As StringBuilder
Dim byteData() As Byte
Dim postStream As Stream = Nothing
address = New Uri("https://www.xxxxxxx.com/api/ajax/widget/refreshWidget")
request = DirectCast(WebRequest.Create(address), HttpWebRequest)
request.Method = "POST"
request.Headers("Authorization") = "Bearer " & "owvNGiOautorizzazoGDNHVGpSO2xcVzE8207JqnjNj"
request.Accept = "application/json"
request.ContentType = "multipart/form-data"
request.Host = "www.xxxxxxx.com"
request.ContentType = "application/x-www-form-urlencoded"
request.Headers.Add("userid", "238")
request.Headers.Add("usernodeid", "1036")
request.Headers.Add("dashboardid", "589")
request.Headers.Add("widgetid", "6699")
data = New StringBuilder()
'data.Append("type: " & HttpUtility.UrlEncode("datatable"))
data.Append(body) 'HttpUtility.UrlEncode(body))
byteData = UTF8Encoding.UTF8.GetBytes(data.ToString())
request.ContentLength = byteData.Length
Try
postStream = request.GetRequestStream()
postStream.Write(byteData, 0, byteData.Length)
Finally
If Not postStream Is Nothing Then postStream.Close()
End Try
Try
response = DirectCast(request.GetResponse(), HttpWebResponse)
reader = New StreamReader(response.GetResponseStream())
Debug.Print(reader.ReadToEnd())
Finally
If Not response Is Nothing Then response.Close()
End Try
with this code i can access to API whit no error,
but i can't receive anythings.