first, i am new with apple in-app purchase. in-app purchase step (is this right?): front processing in-app purchase. front send receipt data to validate on server (server get transaction to check it) confirm purchase to apple the 3rd step i know that front can confirm the purchase. my question: from the the 3rd step, can server confirm it after validated? if it can, how do i imprement it?

in-app purchase: when client commit the purchase, client will send the purchase data to the server, server will get transaction to read the information but when i tested on sandbox, i get the transaction i got { errorCode: 4040010, errorMessage: 'Transaction id not found.' } give me some advice please.