Could not load file or assembly 'System.IO.Ports #2132

   from pythonnet import load
   load("coreclr")
   import clr
   import os
   path = os.path.abspath(os.path.dirname(__file__))
   path = path + r"\dll\myPOSTerminal.dll"
   from myPOS import *
   from myPOS import myPOSTerminal as DotNetMyPOSTerminal

   class myPOSTerminal(DotNetMyPOSTerminal):
     def __init__(self):
        super().__init__()
   terminal =  myPOSTerminal()

  def process_result(r: ProcessingResult):
        # handle the response here
        if r.TranData is not None:
            # transaction response
            print("Transaction response received:", r.TranData)
        else:
            print("NO DATA")

  terminal.ProcessingFinished += process_result
  terminal.Initialize("COM3")

Traceback (most recent call last):
  File "C:\Users\user\Anaconda3\envs\py39\lib\site-packages\IPython\core\interactiveshell.py", line 3441, in run_code
    exec(code_obj, self.user_global_ns, self.user_ns)
  File "<ipython-input-9-1678ee5dc8e5>", line 1, in <module>
    terminal.Initialize("COM3")
System.IO.FileNotFoundException: Could not load file or assembly 'System.IO.Ports, Version=0.0.0.0, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51'. El sistema no puede encontrar el archivo especificado.
File name: 'System.IO.Ports, Version=0.0.0.0, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51'
   at myPOS.myPOSTerminal.Initialize(String ComPort)
   at System.RuntimeMethodHandle.InvokeMethod(Object target, Void** arguments, Signature sig, Boolean isConstructor)
   at System.Reflection.MethodInvoker.Invoke(Object obj, IntPtr* args, BindingFlags invokeAttr)