notification.js

async subscribe() {
            this.error = false;

            if(!this.isLoggedIn || !this.user) {
                return ;
            }

            const onCallCreateNotificationToken = httpsCallable(this.$functions, ON_CALL_CREATE_NOTIFICATION_TOKEN);

            const { data } = await onCallCreateNotificationToken();

            if(typeof data === 'object') {
                this.error = true;
                return;
            }

            const client = connect(
                process.env.STREAM_API_KEY,
                data,
                process.env.STREAM_APP_ID
            );

            this.feed = client.feed('notifications', this.user.uid);

            this.feed.get({ limit: 10 }).then((data) => {
                Object.assign(this.notifications, data);
            });

            this.subscription = await this.feed.subscribe((data) => {
                if (data.new && data.new.length > 0) {
                    this.feed.get({ limit: 10 }).then((data) => {
                        Object.assign(this.notifications, data);
                    });
                }
            }).then(() => {
                console.debug('Notification feed subscription successful');
            }).catch((error) => {
                console.error('Notification feed subscription failed', error);
            });
        },