Hardware back button with Ionic 4

Ionic Framework
66 
import { Platform } from '@ionic/angular';
import { AppMinimize } from '@ionic-native/app-minimize/ngx';
....// blah blah
constructor( private platform: Platform,private appMinimize: AppMinimize) {
            this.platform.backButton.subscribe(()=>{
                // navigator['app'].exitApp();
                this.appMinimize.minimize();
            });
    }
....// blah blah

Try the above code… Its working for me perfectly as the android home button works