We have 5 subcourses like below subcourse1 - 10RS subcourse2 - 20RS Sucourse3- 5RS subcourse4- 11 RS supcouse5 - 12RS If the user selected sourcouse1 and subcourse3 and chose external gateway then we can easily take 15rs payment from external gateway (for any combination of selection of subcourses). Now if user selected subcourse1 , subcourse2, subocourse4 and chosen in app purchase option now we have to take payment of 41rs together. this is not possible unless we create any sku of combination of subcourse1 , subcourse2 and subcourse4. (practically we can create all sku combination for 5 sub courses) for subcourse1, subcourse2 and subcourse3 there are possible combination are subcourse1 subcourse2 3.subcourse3 4. subcourse1 and subcurse2 5. subcourse1 and subcourse3 6. subcourse2 and subcourse3 So we need to create 5 sku in app purchase for taking payment for all user selection combination Now if we have a total of 10 subcourses then there will be multiple combinations (total 3,628,800) . it is not practical to create sku for all 3,628,800 combination please suggest any way to handle my use case or should We prefer external gateway?