Apple Magic Keyboard for older iMac?

I have an older iMac on which the latest macOS that can run is high sierra. This old Mac originally came with a wired keyboard, and I am currently using a third-party wireless, which is starting to have some key problems. I like the compact size of the Apple Magic Keyboard without the numeric keypad, which should fit nicely on my computer desk next to the mouse, but the system requirements on Amazon say MacOS 11.3 or later. Are these requirements for the programmable function keys (which I can do without) and can I get this keyboard to work with the iMac otherwise?