I thought you had given me a way for something that has troubled me repeatedly. Alas no.

On trying to download Mojave from Catalina I get "Update not found. The requested version of macOS is not available."

The system seems to try and be clever and uses software updater, and software updater says I can't have that version.

So how do you get Mojave?

Edit: On further testing, maybe this is a regional issue? I'm not in the US and the link is to the US app Store. This makes the App Store app unhappy ("Cannot connect to app store"). Changing the URL to my region doesn't help. Same issue for all downloads that predate my current version (Catalina). El Cap and Big Sur download nicely.

> Plug the bootable installer into a Mac that is connected to the internet and compatible with the version of macOS you're installing.

Why does it have to be connected to the Internet? The point of using a USB installer is for it to work offline.

> A bootable installer doesn't download macOS from the internet, but it does require an internet connection to get firmware and other information specific to the Mac model.