Use this function when you need to show a certain page, while directing user to Save your App. For example, in e-commerce, when you offer a user to save the app right when the order was places, so he can track the order, you add a target for user to see.
This Targeting ONLY affects the page which is opened for Saving Action. The icon of an app will lead to your HOME page set during creation.
Take any of 2 long links for your app, and add → &pwa_target=https:// where X - is an URL address of the actual page you want to deliver.
For example, - yourapp.mobsted.com/pwa/?appid=19&pwa_target=https://yourwebsite.com/orders/123456 . Following this link will open the target page - yourwebsite.com/orders/123456, but save an app which starts from your home page.
This construct works for both kind of long links, as described here - instant and managed app saving.