Unable to download apps from App Store on macOS 13 or later

I want some applications from app store but I can’t download anything from app store in mac mini late 14 i m using and I can’t able to download excel or any other apps and the popup is says that

that says

(null) can’t be installed on “untitled 2” because mac OS version 13 or later is required.

but I don’t have any update to do update and install app

[Re-Titled by Moderator]