Lookup current Jira Session ID from ACE connect add-on

I’m Developing a Jira (JSM) cloud add-on using ACE. It authenticates to a 3rd party API using OAuth2 - this all works fine but I wish to store the 3rd party auth tokens using the current Jira Session ID as the key. I can’t figure out how to find the current Jira Session ID from my ACE app.

Is there a way to find the current Jira Session ID from an ACE add-on, via rest api or by another means?

I could potentially use the current User ID as the key or store the tokens in the User Properties - but this is not ideal - I want the user to re-authenticate to the 3rd party API every time they login to a new Jira session…

cheers and thanks.