How to send notification to specefic user

Hello guys i'm struggling to find a solution on how to send a notification to a specific user with web-push and and serviceWorker

here's the code (working but everyone can see the notification)

server :

@Post('/notifications/subscribe')
  notif(@Body() body: any) {
    const subscription = body;
    console.log(subscription);

    globals.payload = subscription;

    const payload = JSON.stringify({
      email: subscription.email,
      title: 'Hello!',
      body: 'It workssss.',
    });

    webpush
      .sendNotification(subscription, payload)
      .then((result) => console.log(result))
      .catch((e) => console.log(e.stack));
  }

serviceWorker

self.addEventListener("push", (event) => {
  const data = event.data.json();
  const options = {
    body: data.body,
  };
  event.waitUntil(self.registration.showNotification(data.title, options));
});