Sdkbox Amazon IAP Restore not working

cocos2dx c++ viersion 3.17.1
SDKBOX v1.3.1.0
SDKBOX IAP v2.6.0.1

I am using SDK box IAP for amazon
purchase is successfully done and I get purchase receipt data. this is fine.

now the issue is if I delete the app install again and then try to restore this is not working.
even if I try to click the purchase button I got a message in amazon popup “you already buy this” but in sdkbox I did not get onSuccess() but i get onFailure() callback and also not any msg also in onFailure.

how to restore IAP on amazon
@yinjimmy can you please look this.

@slackmoehrle can you please look this ?

use

sdkbox.IAP.restore()
for restore purchase

@jokerx86
i know the use of that all function of sdkbox
i use this restore() for restore but call back of onRestore() is not calling in amazon IAP
its work in android IAP