Android In-app Billing Subscription Purchase Gives Error [df-aa-20]

I have in-app billing subscriptions available to users which I would like to test and ensure the logic works as expected. However, I am unable to do so. Note: There are a number of

Solution 1:

For testing, use SKU_ID or Product_ID as "android.test.purchased",

there is also library that's easy to use, have a look

https://github.com/anjlab/android-inapp-billing-v3