OptionalappA UUID that you provide to associate with the transaction if the customer accepts the promotional offer.
Note: Use lowercase.
The Base64-encoded cryptographic signature you generate using the offer parameters.
A string that identifies the private key you use to generate the signature.
A one-time-use UUID antireplay value you generate.
Note: Use lowercase.
The subscription offer identifier that you set up in App Store Connect.
The subscription's product identifier.
The UNIX time, in milliseconds, when you generate the signature.
The promotional offer signature you generate using an earlier signature version.
promotionalOfferSignatureV1