SCP Sample C#, it will copy all the files in target folder to a remote server target location via scp and parallelism with max thread count is manageable

scp.cs

using System;
using System.Collections.Generic;
using System.Configuration;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using WinSCP;

namespace YOURPROJECTNAMESPACE
{
    public class SCPEngine
    {
        private string filesPath;

        public SCPEngine()
        {
            filesPath = Path.Combine(Extension.Extensions.AssemblyDirectory, "Storage");
        }


        public async Task ExecuteAsync()
        {
            try
            {
                if (!Extension.Extensions.CheckConnection(Program.GetSettingValue("DestServerIP"), int.Parse(Program.GetSettingValue("DestServerPort"))))
                {
                    Program.Logger.Info($"dest server is unavailable on ip & port that you put in the app config, please check the issue with your network administrator.");
                    return;
                }

                if (!Directory.Exists(filesPath))
                {
                    Program.Logger.Info($"there is no storage folder to processing for SCP.");
                    return;
                }


                var tasks = new List<Task>();               

                DirectoryInfo dir = new DirectoryInfo(filesPath);
                foreach (var file in dir.GetFiles("*.txt").OrderBy(l => l.FullName))
                {
                    tasks.Add(new Task(() => Upload(file)));   
                }

                var maxparallelcopy = int.Parse(Program.GetSettingValue("MaxCopyThread"));
                while (tasks.Any(l => !l.IsCompleted))
                {
                    var innserTasks = tasks.Where(l => !l.IsCompleted).Take(maxparallelcopy).ToList();
                    innserTasks.ForEach(l => l.Start());
                    Task.WaitAll(innserTasks.ToArray());
                }
                    
                Task.WaitAll(tasks.ToArray());


            }
            catch (Exception ex)
            {
                Program.Logger.Error(ex);
            }
        }


        private bool Upload(FileInfo file)
        {
            try
            {
                var lines = File.ReadLines(file.FullName);
                if (lines == null || lines.Count() == 0)
                {
                    file.Delete();
                    return true;
                }

                Session sess = new Session();
                var finger = sess.ScanFingerprint(new SessionOptions
                {
                    Protocol = Protocol.Sftp,
                    HostName = Program.GetSettingValue("DestServerIP"),
                    UserName = Program.GetSettingValue("DestServerOSUser"),
                    Password = Program.GetSettingValue("DestServerOSPassword")
                }, "SHA-256");

                SessionOptions sessionOptions = new SessionOptions
                {
                    Protocol = Protocol.Sftp,
                    HostName = Program.GetSettingValue("DestServerIP"),
                    UserName = Program.GetSettingValue("DestServerOSUser"),
                    Password = Program.GetSettingValue("DestServerOSPassword"),
                    SshHostKeyFingerprint = finger
                };

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

                    TransferOptions transferOptions = new TransferOptions();
                    transferOptions.TransferMode = TransferMode.Binary;
                    //transferOptions.ResumeSupport.State = TransferResumeSupportState.Off;

                    TransferOperationResult transferResult;

                    Program.Logger.Info($"aattempt to upload: " + file.Name + " ...");

                    transferResult =
                        session.PutFiles(file.FullName, $"/{session.HomePath}/parentfoldername/Storage/", false, transferOptions);

                    transferResult.Check();

                    foreach (TransferEventArgs transfer in transferResult.Transfers)
                    {
                        Program.Logger.Info($"Upload of {transfer.FileName} succeeded");
                    }
                }

                Program.Logger.Info($"uploading: " + file.Name + "Finished.");

                file.Delete();

                return true;
            }
            catch (Exception e)
            {
                Program.Logger.Error(e);
                return false;
            }
        }
    }
}