Hey there!
Go to the Microsoft account order history page:
https://account.microsoft.com/billing/orders
Sign in with the same Microsoft account used for the purchase.
Find your Microsoft 365 Home order.
Click Request a refund or Cancel subscription (depending on what is shown).
Follow the on-screen instructions and explain that the purchase was made by mistake.
For more information, please refer:
If you purchased a Microsoft subscription from Google Play or the Apple app store, contact their customer support for cancellation or refund. For Play Store purchases, go to Learn about Google Play refund policies. For Apple App Store purchases, request a refund from Apple support.