private static void transferWinSCP()
{
    string userName = myUsername;
    string password = myPassword;
    string url = ftp://hostname.com/f/fofd671e-0eee-4c23-932d-4ba32c938c8f;
    try
    {
        SessionOptions sessionOptions = new SessionOptions
        {
            Protocol = Protocol.Ftp,
            HostName = "hostname.com",
            PortNumber = 990,
            UserName = userName,
            Password = password,
            FtpSecure = FtpSecure.Implicit,
            FtpMode = FtpMode.Passive,
            TlsHostCertificateFingerprint = "xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx"
        };

        using (Session session = new Session())
        {
            //connect
            session.Open(sessionOptions);

            //upload
            TransferOptions transferOptions = new TransferOptions {TransferMode = TransferMode.Binary};

            TransferOperationResult transferResult = session.PutFiles(@"C:testfile.txt",url, false,
                    transferOptions);
            transferResult.Check(); //ftp error

            foreach (TransferEventArgs transfer in transferResult.Transfers)
            {
                Console.Write("upload of {0} succeeded", transfer.FileName);
            }
        }
    }
    catch (Exception ex)
    {
        Console.Write("error {0}", ex);
    }
}

string path = "/f/fofd671e-0eee-4c23-932d-4ba32c938c8f";
...
session.PutFiles(@"C:testfile.txt", path, false, transferOptions);