code: def check_my_users(user):
      
      user_data = my_users.get(user['username'])
      if not user_data:
          return False  # <--- invalid credentials
      elif user_data.get('password') == user['password']:
          return True  # <--- user is logged in!
  
      return False
docs: Check if user exists and its credentials.
      Take a look at encrypt_app.py and encrypt_cli.py
       to see how to encrypt passwords