Before you can sell in-app purchases or subscriptions on Android, you need to enable billing in your Google Play developer account and connect your Google Billing Key to your app in the Control Panel. This is a one-time setup per app and is required before any Android purchases can be created or used.
Requirements
An active Google Play Developer account
This service is available for specific plans only
How to set up your Google Play account for in-app purchases
Log in to Google Play Console
Select your app
If the app already exists, click into it
If the app does not exist:
Click Create app
Enter an app name and default language
Choose whether the app is free or paid
Accept the declarations and click Create app
In the left navigation, click Monetize with Play, then click Monetization setup
Make sure subscriptions and in-app billing are enabled for the app
Copy the Google Play Licensing Key
Open the Control Panel, then:
Go to Purchases
Paste the key into the Google Billing Key field
Click Save
Pro tips
Android only requires a resubmission the first time you add the Google Billing Key
After this setup is complete, new Android products can be added without rebuilding the appYour app will automatically use this billing key for all Android in-app purchases