Conditional Payment Processing in Flutter: Charging Users Only After Order Acceptance

Hey, I'm using RevenueCat’s SDK on my Flutter app. I want to enable purchases in my app for a physical service. The user can order service, but I want to charge only after an employee of my company accepts the order. If my employee rejects the order, then I don't want to charge the user. Otherwise, I can charge the user upon ordering, but then if my employee rejects it, I'll cancel the purchase and give the user his money back.
Are any of the options available? I cannot find it in the docs. I want to charge the user using the App Store and Google Play.