We released a new build today with this feature. If your license has expired, you'll need to renew your license. Please download a free trial edition in order to test this feature before you renew your license.
If you want to close the browser window automatically after the indexing operation completes, you'll need to pass an additional querystring parameter as below:
Please also make sure you have a copy of Close.Admin.htm file under the Admin folder of your app. You may find a copy of this file under the Controls directory.