Get Azure AD authenticated username from app

I have deployed a Dash app on Azure App Service with AD Authentication, and no basic app dash authentication. I would like to restrict some content based on the user authenticated, and make sure that all states (variables including some large pandas dataframes) can’t be modified by a concurrent user.
Could anyone give a pointer for where to look to retrieve the username from the app?

If you are deploying the app with Dash Enterprise, then its Authentication Middleware allows you to get the username with:

import dash_enterprise_auth

def update_graph(...):

Thanks! That would have been quite easy, however, I am not using Dash Enterprise. Is there any workaround?