Cannot download old versions of MacOS installers

I can't exactly remember which version of the OS this computer came with, but I have verified that it can run High Sierra. If you re-read my original post and review at the screenshots I included, you'll see that I did exactly what you suggest and it doesn't work. The link to the Apple Store opens, but when I click on the "Get" button System Preferences opens and starts "Checking for updates..." There are no updates, since this Mac is running the latest version of Monterey, so I'm not presented with the option to download anything. Thanks for the link to the KB article, but it doesn't appear to work that way anymore.

NO - as I described in the original post *and* in my reply to a previous comment. When I click on the link you provided, it opens the App store on the getting page for High Sierra. I click the "Get" button and that launches System Preferences which starts up "Checking for Updates..." BUT - this mac is on 12.2 so the only updates I see are related to the current version of the OS (if any are available). No sign of High Sierra or any versions of the OS older than the current version.

OK that's helpful. Maybe this machine can't actually run High Sierra. It doesn't show up in the list of available full installers.

% softwareupdate --list-full-installers --force

Finding available software

Software Update found the following full installers:

* Title: macOS Monterey, Version: 12.2.1, Size: 12155426708K, Build: 21D62

* Title: macOS Monterey, Version: 12.2, Size: 12156325205K, Build: 21D49

* Title: macOS Monterey, Version: 12.1, Size: 12157035487K, Build: 21C52

* Title: macOS Monterey, Version: 12.0.1, Size: 12128428704K, Build: 21A559

* Title: macOS Big Sur, Version: 11.6.3, Size: 12435122667K, Build: 20G415

* Title: macOS Big Sur, Version: 11.6.2, Size: 12433351292K, Build: 20G314

* Title: macOS Big Sur, Version: 11.6.1, Size: 12428472512K, Build: 20G224

* Title: macOS Big Sur, Version: 11.5.2, Size: 12440916552K, Build: 20G95

* Title: macOS Catalina, Version: 10.15.7, Size: 8248985973K, Build: 19H15

* Title: macOS Catalina, Version: 10.15.7, Size: 8248854894K, Build: 19H2

* Title: macOS Catalina, Version: 10.15.6, Size: 8248781171K, Build: 19G2021

* Title: macOS Mojave, Version: 10.14.6, Size: 6038419486K, Build: 18G103

It's a MacBook Pro (13-inch, 2018, Four Thunderbolt 3 Ports). I purchased it on 11/26/18.

High Sierra was released in September 25, 2017 and Mojave was released September 24, 2018. So maybe this machine shipped with Mojave.