Dash not working, server not running

I have installed dash and created the demo app, as shown here.

If I run this in a jupyter notebook file I get this error.

Dash is running on http://127.0.0.1:8050/

 * Serving Flask app '__main__'
 * Debug mode: on
/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/traitlets/traitlets.py:2392: FutureWarning: Supporting extra quotes around strings is deprecated in traitlets 5.0. You can use 'hmac-sha256' instead of '"hmac-sha256"' if you require traitlets >=5.
  warn(
/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/traitlets/traitlets.py:2346: FutureWarning: Supporting extra quotes around Bytes is deprecated in traitlets 5.0. Use '296b3779-1181-4cc0-bf64-fe3a278c424b' instead of 'b"296b3779-1181-4cc0-bf64-fe3a278c424b"'.
  warn(
Traceback (most recent call last):
  File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/ipykernel_launcher.py", line 17, in <module>
    app.launch_new_instance()
  File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/traitlets/config/application.py", line 975, in launch_instance
    app.initialize(argv)
  File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/traitlets/config/application.py", line 110, in inner
    return method(app, *args, **kwargs)
  File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/ipykernel/kernelapp.py", line 666, in initialize
    self.init_sockets()
  File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/ipykernel/kernelapp.py", line 307, in init_sockets
    self.shell_port = self._bind_socket(self.shell_socket, self.shell_port)
  File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/ipykernel/kernelapp.py", line 244, in _bind_socket
    return self._try_bind_socket(s, port)
  File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/ipykernel/kernelapp.py", line 220, in _try_bind_socket
    s.bind("tcp://%s:%i" % (self.ip, port))
  File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/zmq/sugar/socket.py", line 229, in bind
    super().bind(addr)
  File "zmq/backend/cython/socket.pyx", line 562, in zmq.backend.cython.socket.Socket.bind
  File "zmq/backend/cython/checkrc.pxd", line 28, in zmq.backend.cython.checkrc._check_rc
zmq.error.ZMQError: Address already in use
/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/IPython/core/interactiveshell.py:3406: UserWarning: To exit: use 'exit', 'quit', or Ctrl-D.
An exception has occurred, use %tb to see the full traceback.

So I tried to put the code on app.py and run it as the comments suggested python app.py

I never get any output on the terminal that the server is running, and If I try to open the localhost url, it never opens anythin.

As the traceback says:

Check if another service is running on same port.

Also, I suggest using jupyter-dash instead of dash.