电容器的背景模式无法正常工作

问：

我尝试在应用程序处于后台且互联网连接已更改时显示通知。当我打开应用程序时，一切正常，但是当我关闭应用程序（在后台）时，没有任何反应

import { Platform } from '@ionic/angular';
import { BaseServiceService } from './../services/base-service/base-service.service';
import { LocalNotifications, LocalNotificationSchema } from '@capacitor/local-notifications';
import { Component, OnInit } from '@angular/core';
import { BackgroundMode } from '@ionic-native/background-mode/ngx';

@Component({
  selector: 'app-home',
  templateUrl: 'home.page.html',
  styleUrls: ['home.page.scss'],
})

export class HomePage implements OnInit {

notificationsDelayInSeconds = '';

constructor(private backgroundMode: BackgroundMode,
  public baseService: BaseServiceService,
  private platform: Platform) {
  platform.ready().then(() => {
    backgroundMode.enable();
    backgroundMode.on('activate').subscribe(() => {
      window.addEventListener('offline', () => {
        this.baseService.scheduleNotification();
      });
    });
  });
 }
}