[keycloak-user] how to force (kind-of) re-activation when user has logged in from a new location ?

Hi all, I'd like : - to detect that a user has just logged in from a new "location" (e.g. userAgent, IP, etc..). - If such event happens, I'd like to make him perform a new account activation, like he did when he registered, i.e. send an activation email. I read in the doc that Keycloak is open and offers the possibility to add custom behavior through plugins.But I don't know where to start exactly ie. - how/where to intercept the login flow to add by own code (i.e. just after the successful authentication) - how to trigger this kind of new activation (probably by adding a required action, but how exactly?) Any leads would be appreciated since I'm discovering Keycloak. I'm currently using KC 2.5.4  + (KC proxy) but no problem to upgrade if necessary. Thanks !