Restapi forbidden response in vb task

I have an API that I tested in Postman. I want to use this API in a task within my own software. I can call the Access Token, CSRF token, and cookies, but when it comes to sending the content I want with this information, I get a forbidden error and I haven't been able to find a solution.

My GetAccessToken function:

   Private Function GetAccessToken() As String            Try                Dim client As New HttpClient()                Dim requestBody As New List(Of KeyValuePair(Of String, String)) From {                    New KeyValuePair(Of String, String)("grant_type", "client_credentials"),                    New KeyValuePair(Of String, String)("client_id", "myclientid"),                    New KeyValuePair(Of String, String)("client_secret", "myclientsecret"),                    New KeyValuePair(Of String, String)("scope", "*")                }                Dim request As New HttpRequestMessage(HttpMethod.Post, "myurl")                request.Content = New StringContent(String.Join("&", requestBody.Select(Of String)(Function(a) a.Key & "=" & a.Value).ToArray()))                request.Content.Headers.ContentType = New Headers.MediaTypeHeaderValue("application/x-www-form-urlencoded")                Dim response As HttpResponseMessage = client.SendAsync(request).Result                If response.IsSuccessStatusCode Then                    Dim result As String = response.Content.ReadAsStringAsync().Result                    Dim tokenResponse As Dictionary(Of String, String) = Newtonsoft.Json.JsonConvert.DeserializeObject(Of Dictionary(Of String, String))(result)                    If tokenResponse.ContainsKey("access_token") Then                        LoggerBase.Log(LogMessage.Types.InfoMessage, Now, 10, "TedasScheduledOutageTask", String.Format("Alınan GetAccessToken : {0}", tokenResponse.ToString()))                        Return tokenResponse("access_token")                    End If                End If                LoggerBase.Log(LogMessage.Types.ErrorMessage, Now, 10, "TedasScheduledOutageTask", "Token alma işlemi başarısız oldu.")                Return Nothing            Catch ex As Exception                LoggerBase.LogUnidentifiedException(ex)                Return Nothing            End Try        End Function

fetchcsrftokenandcookies function:

     Private Function fetchcsrftokenandcookies(token As String) As (String, String)            Try                Dim client As New HttpClient()                Dim request As New HttpRequestMessage(HttpMethod.Get, "myurl")                request.Headers.Add("x-csrf-token", "fetch")                request.Headers.Add("authorization", "Bearer " & token)                Dim response As HttpResponseMessage = client.SendAsync(request).Result                If Not response.IsSuccessStatusCode Then                    LoggerBase.Log(LogMessage.Types.ErrorMessage, Now, 10, "task", "csrf token alma işlemi başarısız oldu.")                End If                Dim cookies As String = String.Join("; ", response.Headers.GetValues("set-cookie").Reverse().Select(Function(c) c.Split(";"c)(0)))'Dim cookies As String = String.Join(";", response.Headers.GetValues("set-cookie").Select(Function(c) c.Split(";")(0)))                Return (response.Headers.GetValues("x-csrf-token").FirstOrDefault(), cookies)            Catch ex As Exception                LoggerBase.LogUnidentifiedException(ex)                Return (Nothing, Nothing)            End Try        End Function

This two function works (I think so) and I can see the results.

But

Post Function:

   Public Overrides Sub ExecuteExtender()            Try                Dim token As String = GetAccessToken()                If String.IsNullOrEmpty(token) Then                    LoggerBase.Log(LogMessage.Types.ErrorMessage, Now, 10, "TedasScheduledOutageTask", "Token alınamadı.")                    Exit Sub                End If                LoggerBase.Log(LogMessage.Types.InfoMessage, Now, 10, "TedasScheduledOutageTask", String.Format("Alınan Token : {0}", token.ToString()))' CSRF Token Al                Dim csrfTokenInfo As (String, String) = fetchcsrftokenandcookies(token)                If String.IsNullOrEmpty(csrfTokenInfo.Item1) Then                    LoggerBase.Log(LogMessage.Types.ErrorMessage, Now, 10, "TedasScheduledOutageTask", "CSRF Token alınamadı.")                    Exit Sub                End If                LoggerBase.Log(LogMessage.Types.InfoMessage, Now, 10, "TedasScheduledOutageTask", String.Format("Alınan CSRF Token : {0}", csrfTokenInfo.Item1.ToString()))                Dim client As New HttpClient()                client.Timeout = TimeSpan.FromMinutes(1)                Dim request As New HttpRequestMessage(HttpMethod.Post, "myurl")                request.Headers.Add("x-csrf-token", csrfTokenInfo.Item1)                request.Headers.Add("Authorization", "Bearer " & token)                request.Headers.Add("Cookie", csrfTokenInfo.Item2)                Dim json As String = "{" & vbCrLf &"  ""date"": ""2024-03-10""" & vbCrLf &"}"                Dim content As New StringContent(json, Encoding.UTF8, "application/json")                request.Content = content                Dim response As HttpResponseMessage = client.SendAsync(request).Result                Dim responseContent As String = response.Content.ReadAsStringAsync().Result                If response.IsSuccessStatusCode Then                    Me.ExecutionStatus = String.Format("Başarılı!")                    LoggerBase.Log(LogMessage.Types.InfoMessage, Now, 10, "TedasScheduledOutageTask", String.Format("ResponseContent : {0}", responseContent.ToString()))                Else                    Me.ExecutionStatus = String.Format("Başarısız!")                    Dim errorContent As String = response.Content.ReadAsStringAsync().Result                    LoggerBase.Log(LogMessage.Types.ErrorMessage, Now, 10, "TedasScheduledOutageTask", String.Format("API çağrısı başarısız oldu. StatusCode: {0}, Hata Mesajı: {1}", response.StatusCode, errorContent))                End If            Catch ex As Exception            End Try        End Sub

and there is a second postdata function I tried before :

     Public Overrides Sub ExecuteExtender()            Try                Dim token As String = GetAccessToken()                If String.IsNullOrEmpty(token) Then                    LoggerBase.Log(LogMessage.Types.ErrorMessage, Now, 10, "TedasScheduledOutageTask", "Token alınamadı.")                    Exit Sub                End If                LoggerBase.Log(LogMessage.Types.InfoMessage, Now, 10, "TedasScheduledOutageTask", String.Format("Alınan Token : {0}", token.ToString()))                Dim csrfTokenInfo As (String, String) = fetchcsrftokenandcookies(token)                If String.IsNullOrEmpty(csrfTokenInfo.Item1) Then                    LoggerBase.Log(LogMessage.Types.ErrorMessage, Now, 10, "TedasScheduledOutageTask", "CSRF Token alınamadı.")                    Exit Sub                End If                LoggerBase.Log(LogMessage.Types.InfoMessage, Now, 10, "TedasScheduledOutageTask", String.Format("Alınan CSRF Token : {0} - Cokiee : {1}", csrfTokenInfo.Item1.ToString(), csrfTokenInfo.Item2.ToString()))                Dim today As String = DateTime.Now.ToString("yyyy-MM-dd")                Dim requestBody As String = $"{{""date"": ""{today}""}}"                Dim client As New HttpClient()                Dim request As New HttpRequestMessage(HttpMethod.Post, "myurl")                request.Headers.Add("X-CSRF-TOKEN", csrfTokenInfo.Item1)                request.Headers.Add("Cookie", csrfTokenInfo.Item2)                request.Headers.Add("Authorization", "Bearer " & token)                request.Content = New StringContent(requestBody, Encoding.UTF8, "application/json")                request.Content.Headers.ContentType = New Headers.MediaTypeHeaderValue("application/json")                Dim response As HttpResponseMessage = client.SendAsync(request).Result                Dim responseBody As String = response.Content.ReadAsStringAsync().Result                If response.IsSuccessStatusCode Then                    Dim result As String = response.Content.ReadAsStringAsync().Result                    LoggerBase.Log(LogMessage.Types.InfoMessage, Now, 10, "TedasScheduledOutageTask", String.Format("Alınan RESULT : {0}", result.ToString()))                Else                    Dim errorContent As String = response.Content.ReadAsStringAsync().Result                    LoggerBase.Log(LogMessage.Types.ErrorMessage, Now, 10, "TedasScheduledOutageTask", String.Format("API çağrısı başarısız oldu. StatusCode: {0}, Hata Mesajı: {1}", response.StatusCode, errorContent))                End If            Catch ex As Exception                LoggerBase.LogUnidentifiedException(ex)                Me.SetStatusText("Görev oluşan hata nedeniyle sona erdi: " & ex.Message)            End Try        End Sub

I tried to copy my accesstoken to postman autharization so it's works. But I don't say my csrf token is valid.