code: def decode_token(self, token):
          
          key = current_app.secret_key
          if key is None:
              if current_app.debug:
                  current_app.logger.debug("app.secret_key not set")
              return None
          try:
              return jwt.decode(
                  token, key,
                  algorithms=[self.config["algorithm"]],
                  options={'require_exp': True}
              )
          except jwt.InvalidTokenError:
              return None
docs: Decode Authorization token, return None if token invalid