How to upload an Image using FTP in asp.net c#

I'm using the below code to upload an image via FTP concept and at the line of code

using (Stream requestStream = request.GetRequestStream())

            {

                requestStream.Write(fileData, 0, fileData.Length);

            }

I'm getting the following error

System.Net.WebException: 'The remote server returned an error: (550) File unavailable (e.g., file not found, no access).'

But I have full access to use this FTP and what I givent the credentials are corrent and also I have conncet through the "FileZilla" and I able to connected to transfer the image also but in the logic implementation I'm getting the above mentioned error I'm unable to understand the error why it is coming

And new to this FTP concept and suggest me how to solve this error

protected void btnUpload_Click(object sender, EventArgs e)

{

    string uidvalue = Convert.ToString(HttpContext.Current.Session["uidvalue"]);

    if (uidvalue == null)

        uidvalue = "000";

    if (fileUploadImage.HasFile)

    {

        string fileName = Path.GetFileName(fileUploadImage.FileName);

        string fileExtension = Path.GetExtension(fileName).ToLower();

        int fileSize = fileUploadImage.PostedFile.ContentLength;

        // Validate file type

        if (fileExtension != ".jpg" && fileExtension != ".jpeg" && fileExtension != ".png")

        {

            lblMessage.ForeColor = System.Drawing.Color.Red;

            lblMessage.Text = "Only .jpg, .jpeg and .png files are allowed.";

            return;

        }

        // Validate file size (<= 2MB)

        if (fileSize > 2 * 1024 * 1024)

        {

            lblMessage.Text = "File size must be 2MB or less.";

            return;

        }

        try

        {

            byte[] fileData = fileUploadImage.FileBytes;

            string ftpUrl = "ftp://abc.com/images_c/" + fileName;

            string ftpUsername = "imguser";

            string ftpPassword = "imguserQ123";

            FtpWebRequest request = (FtpWebRequest)WebRequest.Create(ftpUrl);

            request.Credentials = new NetworkCredential(ftpUsername, ftpPassword);

            request.Method = WebRequestMethods.Ftp.UploadFile;

            request.ContentLength = fileData.Length;

            request.UseBinary = true;

            request.UsePassive = false;

            request.EnableSsl = false;

            request.KeepAlive = false;

            // getting the error in this line 

            using (Stream requestStream = request.GetRequestStream())

            {

                requestStream.Write(fileData, 0, fileData.Length);

            }

            using (FtpWebResponse response = (FtpWebResponse)request.GetResponse())

            {

                lblMessage.ForeColor = System.Drawing.Color.Green;

                lblMessage.Text = "Upload successful: " + response.StatusDescription;

            }

            //lblMessage.ForeColor = System.Drawing.Color.Green;

            //lblMessage.Text = "Upload successful: " + response.StatusDescription;

        }

        catch (Exception ex)

        {

            lblMessage.Text = "Error: " + ex.Message;

        }

    }

    else

    {

        lblMessage.Text = "Please select a file.";

    }

}

Would you like suggestions on how to debug or fix the (550) File unavailable FTP error?