Register PushNotification: Error -> UI API called on a background thread

Ionic Framework
1

Main Thread Checker: UI API called on a background thread: -[UIApplication registerForRemoteNotifications]

I use the following js in constructor in the tab example, but I always get the error as title.
import {
Plugins,
PushNotification,
PushNotificationToken,
PushNotificationActionPerformed } from ‘@capacitor/core’;
const { PushNotifications } = Plugins;

   // Register with Apple / Google to receive push via APNS/FCM
     PushNotifications.register();

//Environment
Ionic:

Ionic CLI : 5.4.15 (/usr/local/lib/node_modules/ionic)
Ionic Framework : @ionic/angular 4.11.10
@angular-devkit/build-angular : 0.801.3
@angular-devkit/schematics : 8.1.3
@angular/cli : 8.1.3
@ionic/angular-toolkit : 2.1.2

Capacitor:

Capacitor CLI : 1.4.0
@capacitor/core : 1.4.0

Anyone can help ?