Upload.cs

using System;
using System.IO;
using log4net;
using WinSCP;

public class Upload
{
	public static void SendFile(UploadConfig config, ILog log)
	{
		try
		{
			var sessionOptions = new SessionOptions
			{
				Protocol = config.Protocol == "FTP" ? Protocol.Ftp : Protocol.Sftp,
				GiveUpSecurityAndAcceptAnySshHostKey = config.Protocol == "SFTP",
				HostName = config.Host,
				UserName = config.User,
				Password = config.Password
			};

			if (!string.IsNullOrEmpty(config.PrivateKeyPath))
			{
				sessionOptions.SshPrivateKeyPath = config.PrivateKeyPath;
				sessionOptions.PrivateKeyPassphrase = config.Password;
			}

			if (!string.IsNullOrEmpty(config.Port))
			{
				sessionOptions.PortNumber = int.Parse(config.Port);
			}

			var txOptions = new TransferOptions 
					{ResumeSupport = {State = TransferResumeSupportState.Off}};

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

				var remoteFile = CreateRemoteFile(
					config.RemotePath, 
					config.ZipFileName);

				log.DebugFormat("Starting transfer of {0} to {1}.", 
						config.ZipFileName, remoteFile);
				
				var result = session.PutFiles(
					config.ZipFileName, 
					remoteFile, 
					false, 
					txOptions);
				
				log.DebugFormat("Transfer result: {0}. ", 
						result.IsSuccess);
			}
		}
		catch (Exception e)
		{
			log.ErrorFormat("Error on Send: {0}", e.Message);
		}
	}

	private static string CreateRemoteFile(string remotePath, string zipFile)
	{
		var remoteFile = string.Empty;
		if (!string.IsNullOrWhiteSpace(remotePath)) remoteFile = 
				RemotePath.AddDirectorySeparator(remotePath.Trim());

		remoteFile += Path.GetFileName(zipFile)?.Trim();

		return remoteFile;
	}
}