Generate signature for Promotional Offer

[rafaeliga]

Hello there,

I see that this library can validate a subscription receipt, but is there a way to generate a signature for Promotional Offer described here?

If not, it would be a good addition(I think I could create a PR for that) to this library or maybe there is other library that does that?

Thanks,

[gabrielgarza]

hello @rafaeliga, its not something I am familiar with or have used in the past, but if you think it makes sense to use with Monza I am happy to review a PR for it.

Best