Processing a Payment through an API?

Does Apple charge a fee (like the 30% fee on in app purchases) if nothing is actually being sold, but just proccessing a money transaction through a third party API that handles credit purchases made on the credit card attached the app? I am not sure whether proccessing a purchase through a third party API will have me avoid the 30% fee. The app is not exchanging money but just transferring it somewhere else.

That would take place outside of the app and not something that would involve Apple, as I see it right, so Apple wouldn't be part of the deal and not expected to take any portion.

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Processing a Payment through an API?
 
 
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