Within my iOS application (currently on testflight) users can can offer their external services, for instance massage treatment, gym sessions etc.
Other users have the ability to buy these services in a form of a voucher which will appear in the application. Users are able to use the service that they payed for by going to the gym or to the masseuse and showing the voucher that is listed in the application under their account.
My question is what form of payment system am I obligated to use? Am I able to use an external payment system like paypal/braintree or the payments have to go through apples in-app purchases?
From what I understand if the goods/services are consumed outside of the application then can/must use traditional credit card entry, paypal or Apple Pay - which is my case.
https://developer.apple.com/app-store/review/guidelines/#goods-and-services
But I can/must use apple in-app purchases when the app offers extra content and features for purchase - so I am not really sure if showing the voucher inside the app after purchase falls into the category of extra content and features?