Hi, I'm John! I will help you with this.
First, could you please confirm where you made the purchase, was it through the App Store on your iPhone/iPad or through iTunes on your computer?
Purchases made through Apple are handled by Apple’s billing system, so Microsoft doesn’t receive the payment details directly. I recommend checking your Apple purchase history to make sure the transaction shows as completed, then take a screenshot or note of the order number.
After that, you can contact Apple Support to verify that the subscription is properly linked to your Apple ID. Once confirmed, sign in to your Microsoft app using the same account that’s connected to your Apple purchase.
Let me know how it goes or if you have any further questions or concerns.