I have found the solution. Here is what I made :
hub:
extraConfig:
oauth.py: |
from oauthenticator.auth0 import Auth0OAuthenticator
from tornado import gen
class CustomAuth0OAuthenticator(Auth0OAuthenticator):
async def pre_spawn_start(self, user, spawner):
spawner.log.debug('BEGIN pre_spawn_start')
auth_state = await user.get_auth_state()
spawner.environment['ACCESS_TOKEN'] = auth_state['access_token']
spawner.environment['ID_TOKEN'] = auth_state['id_token']
spawner.log.debug('END pre_spawn_start')