Android - In App Purchase - you need to add the BILLING permission to your APK

I have been facing a IN - App Purchase problem since long time. I need to integrate In-App functionality in my Android Application, but When I upload the APK file to the play store, it does not allow me to add SKU values. To add in-app products, you need to add the BILLING permission to your APK I have been added "com.android.vending.BILLING" permission in manifest file

1. I downloaded TRIVAL-DRIVER project.
2. Create a new library Project "BILLLING LIBRARY" with my Custom package name eg: Abc.xyz
3. Copy All UTLITY files ALONG .AIDL file[with default package name com.android.vending.billing]in my new Project
4. Gave Reference of that "BILLING LIBRARY" project to MY APPLICATION.
5. Create a signed APK fie and uploaded it to Play Store - [DRAFT]
6. When I go to create SKU values, it gives me the message "To add in-app products, you need to add the BILLING permission to your APK." and doesn't allow to add SKU values.

Any suggestion or tips would be appreciated.

Have you added this line in your manifest file

<uses-permission android:name="com.android.vending.BILLING" />

Since September, 2017 is not necessary anymore to add <uses-permission android:name="com.android.vending.BILLING" />

Play Billing Library 1.0 Release (2017-09-19, Announcement)

Important changes

Embedded billing permission inside library’s manifest. It's not necessary to add the com.android.vending.BILLING permission inside Android manifest anymore.

https://developer.android.com/google/play/billing/billing_library_releases_notes#release-1_0

Just ensure that you are using the latest version of 'com.android.billingclient:billing' in your app gradle configuration file.