Hello, this is koxahe1302, but there's no way to confirm that because I'm using a new account to write this reply. I tried installing WinSCP from the Microsoft store again today and it worked just fine this time.
Are those screenshots from the Microsoft Store webpage or the app? I believe they are from the webpage. Does it work for you with any other application? I assume it does not. Please use the Microsoft Store app to install WinSCP. It should be easier. I've never tried it in the webpage before myself, but now I did and it works too. All my machines were listed on the screen that shows empty on your winscp_msstore_fail_1_of_3.png screenshot.
What a fine piece of software WinSCP is! I've been using it for eons.
I bought WinSCP through the Microsoft store today and Microsoft/its store is not letting me install it from there. Please see the three image files I attached to this post for more information.
Other information: I already have WinSCP installed.