Error in Instagram API - asp.net

Question

I am using asp vb.net and instagram api.
I found a tutorial on instagram api but it is in c#. I tried to convert from c# to VB the best I could but for some reason I am getting an error.
Error: The Remote Server Returned An Error 400 Bad Request
I am getting an error on line:
Dim result = client.UploadValues("https://api.instagram.com/oauth/access_token", "POST", parameters)
My code:
Function GetDataInstagramToken()
Try
Dim parameters As New NameValueCollection
parameters.Add("client_id", Client_ID)
parameters.Add("client_secret", ClientSecret)
parameters.Add("grant_type", "authorization_code")
parameters.Add("redirect_uri", "http://localhost:8979/UI/InstaHome.aspx")
parameters.Add("code", Code)
Dim client As WebClient = New WebClient()
Dim result = client.UploadValues("https://api.instagram.com/oauth/access_token", "POST", parameters)
Dim response = System.Text.Encoding.Default.GetString(result)
'deserializing nested JSON string to object
Dim jsResult As JObject = JsonConvert.DeserializeObject(response)
Dim accessToken As String = jsResult("access_token")
Dim id As Int16 = jsResult("user")("id")
'This code register id and access token to get on client side
Page.ClientScript.RegisterStartupScript(GetType(String()), "GetToken", "<script>var instagramaccessid=\"" + #"" + id + "" + " \ "; var instagramaccesstoken=\"" + #"" + accessToken + "" + " \ ";</script>")
Catch ex As Exception
myLabel.text += "-" &ex.message
End Try
End Function

Answer 1

In this line
client.UploadValues("https://api.instagram.com/oauth/access_token", "post", parameters);
You don't send any value to Instagram. If you check your
parameter, you can see your key but you Can't see any
value.
Try this:
public async void GetTokenFromCode()
{
var values = new Dictionary<string, string> {
{ "client_id","Your ChatId" },
{ "client_secret", "Your Client Secret" },
{ "grant_type", "authorization_code" },
{ "redirect_uri", "Your Redirect url"},
{ "code", "code" } };
var content = new FormUrlEncodedContent(values);
var response = await client.PostAsync("https://api.instagram.com/oauth/access_token", content);
var responseString = await response.Content.ReadAsStringAsync();
}