According to eazystreaming.com article from 20 July 2020
"The Official Roku PC App is now available in your PC's Windows 10 Store which can be downloaded for Free."
I did locate the app in the store, yet it states that it is unavailable. (See image below.) I realize the website could be in error. The article was written 9 days ago, and it appeared to be authoritatively written, yet, the author could have been in error.
Seeing the listing for the app in the Microsoft Store elevated my hopes. I appreciate any research into this app and its availability.