Billing unavailable for this package and user

I’ve tried to implement in-app-purchase-2 with capacitor by following this tutorial:
https://devdactic.com/ionic-in-app-purchase-capacitor/

I’ve placed implementation “com.android.billingclient:billing:3.0.1” in the capacitor-cordova-android-plugins & capacitor-android build grades.

I’ve added <uses-permission android:name="com.android.vending.BILLING"/> to the app & capacitor-cordova-android-plugins manifest files.

The signed app bundle has been published to an open beta track on the google play console and yet whatever user I test the application with I get the following messages in the Logcat:

2020-10-27 22:31:12.219 21963-21981/? I/Finsky: [142] iiy.a(12): com.companyname.appname: Account determined from installer data - [fs-BI1MEaYhqW0Je8svMLxcO8xvkUv-8IOzLR5tovEI]
2020-10-27 22:31:12.219 21963-21981/? I/Finsky: [142] iiy.a(17): com.companyname.appname: Account from preferred account - [fs-BI1MEaYhqW0Je8svMLxcO8xvkUv-8IOzLR5tovEI]
2020-10-27 22:31:12.223 21963-21981/? W/Finsky: [142] inm.j(16): Billing unavailable for this package and user.

I’ve read that the x64 encoded license key from the google console no longer needs to be manually integrated into the code so what else can I do??