public void process(Event event) {
        RealmModel realm = session.realms().getRealm(event.getRealmId());
        UserModel newRegisteredUser = session.users().getUserById(event.getUserId(), realm);
        LOGGER.debugv("Realm: {0}, User: {1}", realm.getName(), newRegisteredUser.getUsername());

        // Push to Apiman, retry a few times.
        Retry.executeWithBackoff(
             (attempt) -> postEventToApiman(attempt, realm, event, newRegisteredUser),
             this::logRetries,
             ATTEMPTS_COUNT,
             INTERVAL_BASE_MILLIS
        );
    }
Process a {@link org.keycloak.events.EventType#REGISTER} and send to Apiman Manager API via HTTP.
sso/keycloak/extensions/src/main/java/io/apiman/manager/sso/keycloak/event/processors/NewUserEventProcessor.java