I have to buy a pc edition, but I bought it with an x-box edition.

Hello you had to check, there are platforms supported. Ubisoft games on PC I have to be purchased from the Ubisoft store.. Then ask for the refund then buy it on Ubisoft.. The Buonon would not work on Ubisoft, but only on the Microsoft Store...

Your best bet is to request a refund from Microsoft then purchase the game from the Ubisoft store or steam.

You cannot get the pc version of the game from the Microsoft Store. You will need to request a refund from here https://support.xbox.com/en-GB/billing/payment-and-purchases/request-refund Then purchase the game from a PC store, like the ubi store here
https://store.ubi.com/uk/home

If you log into your
Microsoft Account page, and then click Payments & Billing > Order History at the top, that will take you to the purchases made on the Windows and Xbox Store. If you find the purchase in question, click "Get order help" underneath the listing and that will
take you to a page that will provide the methods to contact the Billing Department to request a refund. That's the best way to go since the contact methods can vary by region. Not all purchases are eligible, but if you let them know that it was a purchase
for a platform that you don't own and does not work on your device, explaining the situation, that would be your best route.

Where did you buy the game from? The Microsoft Store? I don't think its a play anywhere title.