I can't download MICROSOFT AUTHENTICATOR to my computer
Answer
The Microsoft Authenticator app is something you download on your smartphone, not your computer. When you log into NFC on a computer, a code or similar multi-factor authentication may be accessed via your phone. Basically, keep your smartphone nearby when you try to access your NFC email from a computer.
Microsoft Authenticator Tutorial: my.nicheacademy.com/nfc/course/72197