Вы можете справиться с этим loadtop
const browser = this.iab.create(Your_URL, '_blank', options);
browser.on("loadstop").subscribe((event: InAppBrowserEvent) => {
console.log("Check event Data :", event)
let url = event.url;
if (event.type == "loadstop") {
// handle token
}
}, (error) => {
console.log('some error came up', error)
reject(error);
})