You can't obtain the ISO directly from Microsoft, except through Insider Preview, and I would avoid that. If you select "New" in Parallels, you see the following:
Select "Get Windows 11 from Microsoft" and the ISO is downloaded. I am told this does not come directly from Microsoft but from Parallels, and it is described as a "Retail-OEM" version. It will request activation after a short time, no problem if you have a valid key. Has been working for me since the release in November 2021, but make sure everything works well for you before you pay for anything.