Java Server Socket not connecting

Question

I'm trying to send a message across two computers using Java.net and DataInput/OutputStream but whenever I enter a IP other than localhost it doesn't send. localhost works just fine but when I enter my IP it can't connect. (I am using my external IP and I tested it on the same and different PC's and I'm not using a VPN.)

I would like to know how to get it where I can connect to an IP from a different computer.

EDIT: The IPv6 works but not IPv4. But it's the long one that doesn't show in the findmyip sites & It only works when both programs are on the same system

This is the basic listen part for the message

s = new Socket("localhost", 1201); //heres where the ip goes
            dis = new DataInputStream(s.getInputStream());
            dos = new DataOutputStream(s.getOutputStream());
            String msgin="";
            
            while(!msgin.equals("exit")) {
                msgin = din.readUTF();
                msg_area.setText(msg_area.getText().trim()+"\n Server:\t"+msgin);
            }
            
            } catch(Exception e) {
                e.printStackTrace();
            }
        

This is the write message part, I get the error at dout.writeUTF but that's only when I use a real IP

try {
                    String msgout = "";
                    msgout = msg_text.getText().trim();
                    System.out.println(msgout);
                    dout.writeUTF(msgout);
                } catch (IOException e1) {
                    // TODO Auto-generated catch block
                    e1.printStackTrace();
                }

Heres the error log for the client side:

Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
    at chats.chat_client$2.actionPerformed(chat_client.java:91)
    at java.desktop/javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:1967)
    at java.desktop/javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2308)
    at java.desktop/javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:405)
    at java.desktop/javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:262)
    at java.desktop/javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:279)
    at java.desktop/java.awt.Component.processMouseEvent(Component.java:6631)
    at java.desktop/javax.swing.JComponent.processMouseEvent(JComponent.java:3342)
    at java.desktop/java.awt.Component.processEvent(Component.java:6396)
    at java.desktop/java.awt.Container.processEvent(Container.java:2263)
    at java.desktop/java.awt.Component.dispatchEventImpl(Component.java:5007)
    at java.desktop/java.awt.Container.dispatchEventImpl(Container.java:2321)
    at java.desktop/java.awt.Component.dispatchEvent(Component.java:4839)
    at java.desktop/java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4918)
    at java.desktop/java.awt.LightweightDispatcher.processMouseEvent(Container.java:4547)
    at java.desktop/java.awt.LightweightDispatcher.dispatchEvent(Container.java:4488)
    at java.desktop/java.awt.Container.dispatchEventImpl(Container.java:2307)
    at java.desktop/java.awt.Window.dispatchEventImpl(Window.java:2772)
    at java.desktop/java.awt.Component.dispatchEvent(Component.java:4839)
    at java.desktop/java.awt.EventQueue.dispatchEventImpl(EventQueue.java:772)
    at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:721)
    at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:715)
    at java.base/java.security.AccessController.doPrivileged(Native Method)
    at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:85)
    at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:95)
    at java.desktop/java.awt.EventQueue$5.run(EventQueue.java:745)
    at java.desktop/java.awt.EventQueue$5.run(EventQueue.java:743)
    at java.base/java.security.AccessController.doPrivileged(Native Method)
    at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:85)
    at java.desktop/java.awt.EventQueue.dispatchEvent(EventQueue.java:742)
    at java.desktop/java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:203)
    at java.desktop/java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:124)
    at java.desktop/java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:113)
    at java.desktop/java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:109)
    at java.desktop/java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
    at java.desktop/java.awt.EventDispatchThread.run(EventDispatchThread.java:90)

Heres the error log for the server side:

java.net.ConnectException: Connection timed out: connect
    at java.base/java.net.PlainSocketImpl.connect0(Native Method)
    at java.base/java.net.PlainSocketImpl.socketConnect(PlainSocketImpl.java:101)
    at java.base/java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:399)
    at java.base/java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:242)
    at java.base/java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:224)
    at java.base/java.net.SocksSocketImpl.connect(SocksSocketImpl.java:403)
    at java.base/java.net.Socket.connect(Socket.java:609)
    at java.base/java.net.Socket.connect(Socket.java:558)
    at java.base/java.net.Socket.<init>(Socket.java:454)
    at java.base/java.net.Socket.<init>(Socket.java:231)
    at chats.chat_client.main(chat_client.java:46)