[Solved] Can not go on with Google promo code

[AdnanMauGames]

Hey all,
Hope you are doing well.
I am working with Unity IAP and everything is okay when i tried to buy from my credit card but i want to test the promotion code for Google Play.
I can only see the option of “Add Credit Card” what can i do to enable promotion code or “Redeem Code”.

Thanks,

[ap-unity]

@AdnanMauGames

You can redeem promo codes, including for in game items, in the Google Play Store. They should be detected when the user launches your app. If your app is not installed, then the user will be directed to the download page in the Google Play Store.