Transfer a file from a local machine to an Ubuntu virtual machine using the FTP protocol through a Java program

package org.example;import org.apache.commons.net.ftp.FTPClient;import java.io.File;import java.io.FileInputStream;import java.io.IOException;public class FTPFileUploader {    public static void main(String[] args) {        long startTime = System.currentTimeMillis();        String server = "192.168.142.128";        int port = 21; // Port FTP par défaut        String user = "youssef";        String pass = "youssef";        String localFilePath = "C:/Users/DeLL/Desktop/wewe.txt";        String remoteDirectory = "/home/youssef/Desktop/you";        FTPClient ftpClient = new FTPClient();        FileInputStream fis = null;        try {            ftpClient.connect(server, port);            ftpClient.login(user, pass);            ftpClient.enterLocalPassiveMode();            File localFile = new File(localFilePath);            fis = new FileInputStream(localFile);            String remoteFileName = localFile.getName();            ftpClient.storeFile(remoteDirectory +"/" + remoteFileName, fis);            long endTime = System.currentTimeMillis();            long scpTime = endTime - startTime;            System.out.println("la durer de transformation de fichier : " + scpTime+" ms");        } catch (IOException e) {            e.printStackTrace();        } finally {            try {                if (fis != null) {                    fis.close();                }                ftpClient.logout();                ftpClient.disconnect();            } catch (IOException e) {                e.printStackTrace();            }        }    }}

java.net.ConnectException: Connection timed out: no further information at java.base/sun.nio.ch.Net.pollConnect(Native Method) at java.base/sun.nio.ch.Net.pollConnectNow(Net.java:672) at java.base/sun.nio.ch.NioSocketImpl.timedFinishConnect(NioSocketImpl.java:554) at java.base/sun.nio.ch.NioSocketImpl.connect(NioSocketImpl.java:602) at java.base/java.net.SocksSocketImpl.connect(SocksSocketImpl.java:327) at java.base/java.net.Socket.connect(Socket.java:633) at org.apache.commons.net.ftp.FTPClient._openDataConnection_(FTPClient.java:866) at org.apache.commons.net.ftp.FTPClient._storeFile(FTPClient.java:1053) at org.apache.commons.net.ftp.FTPClient.storeFile(FTPClient.java:3816) at org.apache.commons.net.ftp.FTPClient.storeFile(FTPClient.java:3846) at org.example.FTPFileUploader.main(FTPFileUploader.java:31)

I have checked network connectivity. I have verified network configuration settings. I have checked the firewalls on my Ubuntu virtual machine.

Why did the file not transfer to the Ubuntu virtual machine?