How to download and install updates to these Apple apps in this macOS without an Apple ID? Can I download the installer? If so, from where exactly?

Solution 1:

The linked question bypasses the App Store, because merely owning a Mac entitles you to macOS. You can also get any of these through Software Update in the Control Panel. You'll note you can only get delta & combo updaters there, not entire installers for the whole OS - for that you need the App Store, or to boot from Recovery.

To update any app from the App Store, first you need to be signed in to the Apple ID that "purchased" it, even if that purchase was free, or it came pre-loaded on the Mac. The only exception I can think of to this might be Safari, which seems to come through the Software Update channel rather than the App Store.