How to activate Windows ARM key?

I put a fresh copy of Parallels on a new M1 Air. I downloaded and installed the M1 preview build, which is Win 10 pro. How do I activate it? If I buy Win 10 pro, does that come with an activation key that I can enter? As it is it's pretty useless because I can't "personalize" or customize anything. I can't even sign in with my password because it's not activated. Two days with MS support have made me realize (again) how great Apple tech support is, and how utterly awful MS support is.

So any help appreciated!

 

Great, thanks! Is Win 10 pro the same as Win 10 pro for business? That's the only one on the MS store that I could find. Sorry, I know next to nothing about MS stuff.

 

If you go through the Windows store you may end up paying $300 for Windows Pro. When I did a search on "Windows 10 download" there was a link to an MS page that charged me only $199.00. This is the Windows pro key that I used to activate my ARM64 build just yesterday. ( https://www.microsoft.com/en-us/d/windows-10-pro/df77x4d43rkt?rtc=1&activetab=pivot:overviewtab ) Just thought you might want to be aware of the discrepancy.

 

If I use my legitimate Win10 Pro license key from a previous Parallels Win10 Pro VM for the Win11 Pro Insider Edition ARM running in Parallels on an M1 MacBook Pro M1 Max will Microsoft DE-ACTIVATE my "donor" Parallels Win10 Pro VM ???

I really need to be able to run my Parallels Win10 Pro VM to run TurboTax Business (which is Windows ONLY) for another 6 months (end of U.S. tax season) JUST IN CASE Microsoft discontinues Win11 Pro Insider Edition ARM support