Hello;
Welcome to the Microsoft Community! I'll be glad to assist you today! Microsoft has put out Generic Product Keys which allow you to install Windows, but the keys will not activate Windows 10, you'll need to purchase an official OEM version of the OS in order to be activated. You can find the list of Generic Keys Here. Look under the column that says "Retail", and copy and paste the key for your edition of Windows 10. Hope this helps!
Sincerely,
Dustin Bumgarner
Windows Insider