I get an error when running python_serial.py

[psm12]

First, I must apologise, i'm not a programmer.

I get an error running this (Python 3.14):

Exception has occurred: AttributeError
'NoneType' object has no attribute 'port'
File "C:\Python_serial\python_serial\python_serial.py", line 260, in
port=args.port,
^^^^^^^^^
AttributeError: 'NoneType' object has no attribute 'port'

Can you help? thanks.