I’m using Nuget package FtpSharpLib.Core, and this is my code:

FtpCredential ftpCredential = new FtpCredential();
FtpClient _client = new FtpClient(ftpCredential.Host, ftpCredential.Username, ftpCredential.Password);

var localFilePath = @"C:UsersKOWDownloadsnil tech it.jpg";
var remoteFilePath = "/test folder";

await _client.Connect();
await _client.UploadFile(localFilePath, remoteFilePath);
await _client.Disconnect();

I get an error

550 – The filename, directory name, or volume label syntax is incorrect