Hello
Windows license is typically not refundable, so you will not find the request refund option in your account's order history.
Open the "Get Help" app on your computer (just search for it in the Start menu). or go to https://support.microsoft.com/contactus, Type "Billing" and press Enter. On the next screen, click "Contact support" at the bottom of the page, then choose "Windows" > "Manage my subscription". You’ll then see the option to chat with a Microsoft support agent. Explain that it was an accidental purchase. They might make an exception for you by refunding it manually.