Your private key downloaded from App Store Connect
Your private key ID from App Store Connect
Your issuer ID from the Keys page in App Store Connect
Your app's bundle ID
Create an introductory offer eligibility signature.
The unique identifier of the product
A boolean value that determines whether the customer is eligible for an introductory offer
The unique identifier of any transaction that belongs to the customer. You can use the customer's appTransactionId, even for customers who haven't made any In-App Purchases in your app.
The signed JWS. Generating JWS to sign App Store requests
Protected
internal
Create a IntroductoryOfferEligibilitySignatureCreator