subscriptionGroupIdentifier string - The identifier of the subscription group to which the subscription belongs.
subscriptionPeriodProductSubscriptionPeriod (optional) - The period details for products that are subscriptions.
isDownloadable boolean - A boolean value that indicates whether the App Store has downloadable content for this product. true if at least one file has been associated with the product.
downloadContentVersion string - A string that identifies the version of the content.
downloadContentLengths number[] - The total size of the content, in bytes.