How can I check the user has preorder in production app when app is free and user who has purchased nothing?

Hello.

I has a plan to release the app with pre-order. And I want to give the user who has preorder to some reward. So I have research about preorder.

Related Doc:

• Offering Your Apps for Pre-Order

The preorder_date receipt field helps you identify customers who pre-ordered your app. You can use this information to unlock rewards — such as additional coins in a game — for pre-order customers or display in-app messaging to thank them for their purchase.

• responseBody.Receipt

preorder_date The time the user ordered the app available for pre-order, in a date-time format similar to ISO 8601.

• Validating Receipts with the App Store

Fetch the Receipt Data To retrieve the receipt data from the app on the device, use the appStoreReceiptURL method of NSBundle to locate the app’s receipt, and encode the data in Base64. Send this Base64-encoded data to your server.

I have read these doc and tested verifyReceipt API. Now I know how to verify receipt and how to check if whether preorder date is presented.

However, I cannot know the user has always receipt data. I have tested fetching the receipt data in Xcode and TestFlight when user is just installed first time. Result is fail and throw error like below:

appStoreReceiptUrlNotFound(url: "/private/var/mobile/Containers/Data/Application/XXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXX/StoreKit/sandboxReceipt")

Unfortunately, I have not found yet how to test for fetching receipt data in preorder status.

Now I have question about preorder.

1. If app is free and user has purchase nothing, can I fetch receipt data in production app?
2. If the data cannot be fetched, should I wait the user purchasing something for checking preorder?

Or if someone know how to test this in preorder status, please let me know it.

Thanks for reading.