Hi. I am currently developing the first version of my company's IOS app (up until now we have been a web only platform). In our current subscription model, businesses subscribe to a tier and it includes usage of the platform for X amount of members of that business. If the business exceeds that number of included members, each additional one is billed to the business at the end of the billing cycle for an extra cost. I have been looking into using in app purchases (seems like I am forced too use them), and cannot see an obvious way to implement this. Stripe for example offers this by reporting usage to their backend for a particular subscription and dynamically bills the correct amount at the end of the billing cycle. Has anyone had experience with implementing something like this with in-app purchases? Thanks in advance.