Keycloak 3.4.3 keep session on JDBC databaase?

Hi, I have an old Keycloak v3.4.3 in Debian. Unfortunately I cannot upgrade to a recent version, at the moment.

I need a way to delete a particular user session, via an API? or if I can setup Keycloak to store the user sessions on my JDBC (MySQL) database where the rest of the data is store, then I can some external mechanism to delete the session which is store on the database.

Why I need this is very complex, involve our website and a mobile app where the user can jump from the Website to the mobie - deeplinking; when the user is logging out from the mobile app, I need a way to force to logout from the Keycloak session which reside on the mobile web-browser e.g, if the session on is store on the databases, I can have an API to delete that session from the database, from where I can tell, my Keycloak by default is storing the sessions in memory?

If anybody can provide me some clues, I will highly appreciate it.

Thanks,