IAP not work on Unity

I followed Unity IAP guide hear and I also watched some blog including this and this one to know how to integrate IAP in Unity.
*But when I build APK and upload it to seller portal, it’s said “this binary is not support IAP”. Please help me out

I checked with the seller Portal IAP team and they said,

If you have integrated our Unity plugin properly and still getting an error message at Seller Portal, then I’d recommend to check the following steps From this integrate iap helper guide
Add permissions to AndroidManifest.xml
Register an app and in-app items in Seller Portal

If those are correct then you need to open a technical support request for the team.

Samsung Developer Relations