Microsoft Store purchases
All purchases are managed by the Microsoft Store, and we don’t have access to any purchase details, but if you have subscribed to Chordle and are seeing demo banners in the app like this:

First, make sure that you are signed into the Microsoft Store with the same account you used to make the purchase. You can double-check that your purchase was from the expected account by visiting your Microsoft Store account page.
If the purchase was successful, try tapping Restore subscription in the dialog that opens when you tap Unlock full version.

If that still doesn’t work, please contact Microsoft support for Store license issues.