code: def create_jwt(self, expires_in=None):
          
          s = utils.sign_jwt(data={"id": self.user.id},
                             secret_key=get_jwt_secret(),
                             salt=get_jwt_salt(),
                             expires_in=expires_in or get_jwt_ttl())
          return s
docs: Create a secure timed JWT token that can be passed. It save the user id,
          which later will be used to retrieve the data
  
          :param user: AuthUser, the user's object
          :param expires_in: - time in second for the token to expire
          :return: string