Hello,
Welcome to Microsoft Q&A!
Can I use a third party IAP for games or do I have to use Microsoft’s?
Based on the Store policy 10.8.1. it is mentioned that Non-game in-app products made available on PC devices may either use a secure third-party purchase API or the Microsoft Store in-product purchase API for in-app purchases of digital items or services that are consumed or used within the product.
Please check these policies for more information about the in-app purchases: Financial Transactions.
Thank you.
If the response is helpful, please click "Accept Answer" and upvote it.
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.