Question Can I redeem code for Xbox game on PC? Forza Horizon 4


The title is not very detailed I know, but had to go with something that would sum up a part of my question to make it understandable lol.

So basically I want to buy Forza Horizon 4 for PC, but I don't want to buy the Ultimate Edition retail from the Microsft Windows Store.
Instead I plan to buy a key for it from a key site which will cost the $60 instead of $100.
I don't want to hear anything out of anyone about their opinions on key sites and blah blah blah, I'm only telling you so you know what I'm dealing with here.

Now as far as I could figure out, the code is both redeemable for Xbox and for PC but I would like some clarification from anyone who actually may know a thing or two about this.

If I buy the code, will it only redeem for Xbox when I redeem online in the store or will it redeem for PC?
Will it redeem for both or will it maybe give me a choice as to which digital version I want?

There is this thing about play anywhere, if the code only redeems for Xbox, will I still be able to play on my PC?
Do I need to get game pass or pay some kind of subscription to anything?

The details aren't very clear anywhere on the internet about this and obviously so since most people who would buy the codes would buy them to redeem on their Xbox consoles, or people would just buy directly from the store on PC.

So basically if I buy the key for digital, can I simply redeem it on PC store or can it only be redeemed through Xbox?
If only Xbox, I can obviously redeem online through Xbox website and my account, but then will it be playable on PC without having to do anything else?
I don't have an Xbox One so if it would require anything special using the console, or with paying for some kind of service to allow me to play it on PC then I'm not gonna do that.