Read value of custom cookie in refresh_user

Hello, I’m currently trying to integrate Jupyterhub into our main platform. We have a JWT token that is stored in a cookie on our top-level domain. Since JupyterHub is hosted as a sub-domain of our main app, it should have access to this cookie. I’m currently trying to read the value of this cookie in the ‘refresh_user’ method of our custom Authenticator class in order ensure that the current user’s session is still valid. How would I retrieve the value for this cookie? Here is my current pseudocode

def is_valid_token(token):
  # do an API call to main app to validate token
  is_valid = api_request(token)
  return is_valid

async def refresh_user(self, user, handler, force=True):
  token = # how to read the value from cookie named 'sessionToken' here?
  if not self.is_valid_token(token):
     return False
  return True

My apologies, i asked this question because i was trying to use ‘handler.get_cookie’ which kept returning None, but it turns out that my actual test attempts were being pushed away by one of our status monitoring tools that makes a request to the same path (but without setting a cookie) and therefore the value kept showing up as ‘None’ in the logs. But it turns out that handler.get_cookie actually does return the correct value for the cookie.