Same issue as well. In the Testflight with Sandbox account, there was no issue with the purchase. The only they gave to me is just the screenshot of when the purchase failed. error code 0 , "An unknown error occurred" Is there anything that I missed? please help me

the Same issue as well. how to fix , please help me

In-App Purchase failure in the apple's review, when the purchase failed, error code 0 , "An unknown error occurred", but works in the Testflight&sandbox. Is there anything that I missed？ anyone found a solution， Thanks for your help AppleD:1557609456