Hi ,
I'm Dyari. Thanks for reaching out. I will be happy to assist you in this regard.
Microsoft PIN is a local security method called Windows Hello PIN, used instead of a password to sign in to your device, apps, or Microsoft services. Where does it specifically ask for a PIN?
If you are on the login screen for your computer, you need to enter the user account PIN that you set up previously. It is not a Microsoft account nor a support PIN. You can’t view your current PIN for security reasons, but you can change or remove it:
Please feel free to ask if you need further assistance.