How to link a suitable device to your Microsoft account?

I wanted to download Fortnite Battle Royale from the Xbox Store on my PC. But when I clicked "Install on my device," I could not download it because I did not associate a suitable device with my Microsoft account. I did not know if my device was out of date or if I did not connect my device.

Fortnite but there are synonymous for the PC? On Epicgames, there you can log in with your Xbox account, normal would then have to be the same as on the Xbox