This is an add-on feature of Notificare. You will need to subscribe to this add-on as described here before you can use this functionality. With the Monetize add-on you can easily manage and sell virtual goods in Google Play. Our library will provide all you need to use the Google's In-App Billing API to sell digital goods directly from your app.
Please note that be able to test In-App Billing, you will need to upload at least an Alpha build of your app to Google Play.
If you meet the requirements above, go ahead and learn how to setup Notificare's Monetize add-on and create products for Google Play by proceeding to the Setup guides.