@Bean
        @RefreshScope(proxyMode = ScopedProxyMode.DEFAULT)
        @ConditionalOnMissingBean(name = "firebaseCloudMessagingNotificationSender")
        public NotificationSender firebaseCloudMessagingNotificationSender(
            final CasConfigurationProperties casProperties) throws Exception {
            val firebase = casProperties.getGoogleFirebaseMessaging();
            val options = FirebaseOptions.builder()
                .setCredentials(getCredentials(casProperties))
                .setDatabaseUrl(firebase.getDatabaseUrl())
                .build();
            val firebaseApp = FirebaseApp.initializeApp(options);
            return new GoogleFirebaseCloudMessagingNotificationSender(firebase, firebaseApp);
        }
This is {@link CasGoogleFirebaseCloudMessagingAutoConfiguration}.

@author Misagh Moayyed
@since 6.3.0
support/cas-server-support-notifications-fcm/src/main/java/org/apereo/cas/config/CasGoogleFirebaseCloudMessagingAutoConfiguration.java