connect to an sftp server and upload a file, but don't overwrite existing files in csharp

main.cs
using Renci.SshNet;
using System.IO;

// Establish a connection to the SFTP server
var connectionInfo = new ConnectionInfo("hostname", "username", new PrivateKeyFile("private_key_file_path"));
using (var client = new SftpClient(connectionInfo))
{
    client.Connect();

    // Check if the file already exists on the server
    string remoteFilePath = "/path/to/remote/file.txt";
    if (client.Exists(remoteFilePath))
    {
        // If the file already exists, generate a new unique name for the uploaded file
        string fileName = Path.GetFileNameWithoutExtension(remoteFilePath);
        string fileExtension = Path.GetExtension(remoteFilePath);
        remoteFilePath = $"{fileName}_{DateTime.Now:yyyyMMddHHmmss}{fileExtension}";
    }

    // Upload the file to the SFTP server
    using (var fileStream = new FileStream("path/to/local/file.txt", FileMode.Open))
    {
        client.UploadFile(fileStream, remoteFilePath);
    }

    client.Disconnect();
}
969 chars
28 lines