How to listen to inAppBrowser closed event

There are few things that is wrong in your code.

From the documentation browser.hide() doesn't do what you want to do.

Hides an InAppBrowser window that is currently shown. Calling this has no effect if the InAppBrowser was already hidden.

_blank replace it with _system because _blank opens in the inAppBrowser. You won't be able to listen for close event.

Now, you can subscribe to the browser and listen for it's events e.g.

//Events: loadstart, loadstop, loaderror, exit
browser.on('exit').subscribe(() => {
    console.log('browser closed');
}, err => {
    console.error(err);
});

I know it to late this issue was 3 years ago but the issue is an issue so here is the solution

1st import InAppBrowser

import {InAppBrowser} from '@ionic-native/in-app-browser/ngx';

2nd add to constructor()

constructor(private iab: InAppBrowser ) {}

3rd Now you can use on('xxx') where xxx is the event you want Events list: 'loadstart' | 'loadstop' | 'loaderror' | 'exit' | 'beforeload' | 'message' | 'customscheme'

In your case, you want to listen when inAppBrowser is closed check follwoing example:

anyFunName(url){
let openBrowser = this.iab.create(url, '_blank');
openBrowser.on('exit').subscribe(event => {
  console.log("inAppBrowser is closed now");
  // your action here when close inAppBrowser
});
}