code: def encrypt_string(self, concatenated_str):
          
  
          # Convert string to bytes
          concatenated_bytes = concatenated_str.encode()
  
          # Encrypt, timestamp, sign, and base64-encode
          encrypted_bytes = self.fernet.encrypt(concatenated_bytes)
  
          # Convert bytes to string
          encrypted_str = encrypted_bytes.decode('utf-8')
  
          # Remove '=' padding if needed
          token_str = encrypted_str.strip('=')
          return token_str
docs: Timestamp, sign and encrypt a string into a token using ``cryptography.fernet.Fernet()``.