error windows 10

[learnercrypto]

database size: 23180116
processes spawned: 8
Process Process-1:
Traceback (most recent call last):
File "C:\Users\Barthwal\AppData\Local\Programs\Python\Python310\lib\multiprocessing\process.py", line 314, in _bootstrap
self.run()
File "C:\Users\Barthwal\AppData\Local\Programs\Python\Python310\lib\multiprocessing\process.py", line 108, in run
self._target(*self._args, **self._kwargs)
File "D:\abhi\plutus NEW\plutus.py", line 65, in main
address = public_key_to_address(public_key)
File "D:\abhi\plutus NEW\plutus.py", line 31, in public_key_to_address
encoding = binascii.unhexlify(public_key.encode())
AttributeError: 'NoneType' object has no attribute 'encode'