Re-use Login (and HTTPS) for co-located app

I love z2jh and have gotten a hub running on GKE, using oauth with our org’s gSuite. In addition to jhub, there is a related Flask app that is running by its side on the same domain (myapp.mydoman.edu and jhub.myapp.mydomain.edu).

Is there any hope that I can re-use the login done via jhub for both apps? I’d like users to sign-in once and get access to both jhub and the Flask app. (Bonus points if the letsencrypt https setup can be re-used).