Sorry, I realize I asked you to check the wrong thing
Again, the purpose here is simply to check if you have a "Microsoft Live" account (which would be needed to acquire and use MSFS through the MS Store).
So let's check again, in a different way:
I took a look on my own computer just now to use that as an example, because from my side, I login into my Windows 10 using a Microsoft account, not a local account.
To verify that, I went to my Windows settings (from the Windows Start menu), then into Accounts.
In there, I could see my account profile picture, with my name under it, and my email address under that.
Also, a few lines lower, there is a blue link telling "Connect using a local account instead" or something like that (mine is in another language, so I'm not sure how to properly translate
This indicates I am NOT logged through a local account, and that I'm logged through my Microsoft account instead.
How is it on your side ?
If you can also see your email address under your name, and also that blue link proposing to log in via a "local" account (don't
click on it!!), then it means you are also logged in through a Microsoft account, which would be perfect.