Subscription to push using SwPush

control-push.component.ts

import { SwPush } from '@angular/service-worker';
...

  // Injecting SwPush dependency

  constructor(private pushService: PushService, private swPush: SwPush) {}

  subscribeToPush() {

    // Requesting messaging service to subscribe current client (browser)

    this.swPush.requestSubscription({
      serverPublicKey: this.VAPID_PUBLIC_KEY
    })
      .then(pushSubscription => {

        // Passing subscription object to our backend

        this.pushService.addSubscriber(pushSubscription)
          .subscribe(

          res => {
            console.log('[App] Add subscriber request answer', res)

            let snackBarRef = this.snackBar.open('Now you are subscribed', null, {
              duration: this.snackBarDuration
            });
          },
          err => {
            console.log('[App] Add subscriber request failed', err)
          }

          )
      })
      .catch(err => {
        console.error(err);
      })

  }