If you want to monetise your app by selling it in the Google Play Store, there are a few additional steps you have to follow. In this situation, you need an additional Google Merchant account.
>> Please note: You cannot convert an already published free app to a paid one. <<
Create an app record in the Google Play developer console.
You'll first have to create the app within the Google Play developer console. To do so, you can follow the steps in the regular publishing documentation available in our help center. Make sure not to publish the app yet, as we will have to set a price for the app before doing so.
Making your app paid, and setting a price.
- Login on https://play.google.com/apps/publish with your Google Play developer account.
- Select your app from the list, navigate to the Monetize section within the left-side menu, and open the App Pricing page.
- On the App Pricing page, click the 'Make your app paid' option for your app and enter the price.
- Once you've set the price for your app, save your changes.