How to plug logic into session invalidation due to cookie expiration

Question

In my app, I want to send some request to the api on session invalidation.

I want to be able to differentiate when a user logs out (clicks on the button), and when he is automatically logged out (eg, after inactivity period, cookie expiration...)

I think I've managed most of the use cases, the only remaining one is to be able to 'plug' some logic when the cookie expires, but before the session is cleaned-up.