Ionic native network plugin

I need to check internet and id connection exist I need to perform a server request. I used ionic native network Plugin. But i done as per their official doc.

my CODE:

import { Component } from '@angular/core';
import { IonicPage, NavController, NavParams, LoadingController } from 'ionic-angular';
import { Auth } from '../../providers/auth/auth';
import { Network } from '@ionic-native/network';
@Component({
  selector: 'page-login',
  templateUrl: 'login.html',
})
export class LoginPage {
  constructor(private network: Network,private alertCtrl: AlertController,public navCtrl: NavController, public navParams: NavParams,public authService: Auth, public loadingCtrl: LoadingController) {
  
}
  ionViewDidLoad() {
      // watch network for a disconnect
    let disconnectSubscription = this.network.onDisconnect().subscribe(() => {
        console.log('network was disconnected :-(');
    });
  disconnectSubscription.unsubscribe();
  // watch network for a connection
  let connectSubscription = this.network.onConnect().subscribe(() => {
    console.log('network connected!');
    //Check if already authenticated
    this.authService.checkAuthentication().then((res) => {
        console.log("Already authorized");
        this.loading.dismiss();
        this.navCtrl.setRoot(HomePage);
    }, (err) => {
        console.log("Not already authorized");
        this.loading.dismiss();
    });
  });
  
  // stop connect watch
  connectSubscription.unsubscribe();
    console.log('ionViewDidLoad LoginPage');
  }
}

Here it does not even entering into onConnect!! Why does this happen?

If this is the first page of your app the Cordova plugins might not yet be ready. Try to wrap your first call with network inside this block:

this.platform.ready().then(() => {
  // Do your network stuff now
});

Of course make sure you add the platform to your constructor as well (like in app.component.ts)!

Error shows in this as:

Unexpected token. A constructor, method, accessor, or property was expected.