Hook for Scriptcalls or a curl based API-Call in Users Password Change/Update Function?

Hi!
I´m running a 24.0.1 keycloak system (3 nodes) where a mailservercluster (on same nodes) running postfix/dovecot/roundcube (using galera db) which actually is managed via postfixadmin.
Postfixadmin is used as the servers are configured with quotas and several virtual domains and where only some domains use oauth via roundcube (was a struggle to get this to work but i managed it ;.-) ) .
The problem i have now is that if a user changes his password in keycloak the passwords stored in the mailservers db are not simultanously upgraded.
I need a hint how to integrate a hook inside the “change/update password” function of keycloak where the new password will be synchronised, either via a systemcall which starts a script using postfixadmin-cli on the actual node or via an curl-call with apikey etc. towards postfixadmin.

The only plugins for keycloak i had found up to now where eventlisteners which said they support webhooks but i guess thats only for logging events and seemed not to have anything configurable anywhere in the keycloak realmadministrationsinterface.
How can i manage the task then?
Actually i tried to figure out if there might optionally be a way to use an api for calling the passwordupdate by the authenticated user themselves from a self written script or so, but it seems passwordchanges are not supported via api-calls in keycloak for security-reasond (as i already expected ;-))

Best solution would be if the desired functionality works bounded to individual groups inside keycloak to have additional individual options, like upgrading the quotas etc., but i lack of information how this could be done up to now.

Maybe someone here has some good hints for me?

Thanks in advance,
Tom