Seemingly random exceptions at fernet token from file

Question

Please excuse my poor english and spaghetti code;

I really want to make a python script that encrypts and decrypts files, but every time i try to run it (in vs code), there is one or another problem with the token.

Here is the code:

import os
from cryptography.fernet import Fernet

defKey = 'wLQz9Enb5veyv_JhXKsYMWybwAhm-JA1ytdyh4tGRI0='

def dec():
    inpPass = input('Password:\n')
    passKey = inpPass + defKey[len(inpPass):]
    
    passToken = open('pass.txt', 'rb').read
    Fernet(passKey.encode('utf-8')).decrypt(passToken)
    print('no error wowie')

dec()

The exception with this code here is TypeError: token must be bytes.

Quite detailed explanation:

The pass.txt file contains the word "check" encrypted with this key: amogusnb5veyv_JhXKsYMWybwAhm-JA1ytdyh4tGRI0=. The script is prompting the user to enter a password. The password gets converted to a fernet key by replacing the first letters of defKey. After that the program tries validating the key by decrypting the pass file.

I tried three notable things:

1. Making the pass.txt file plaintext in the script, and converting it to bytes. This worked, but i want the script to take in different passwords.

2. Converting the file to string, then to bytes.

Fernet(passKey.encode('utf-8')).decrypt(bytes(str(encPass), 'utf-8'))

This gives this exception: InvalidToken: Incorrect padding.

3. Doing what i did previously, but adding an equals sign to the string. This gives InvalidToken: no description. I thought about adding this because is solved somebody's problem with decoding base64.

Please help! I am really stuck, and for no good reason.