Installing Garage Band on late-2011 Macbook Pro with Sierra 1012.6 — problems

Hello,

I have a late-2011 MacBook Pro with 16gb ram, 500gb HDD, running Sierra 12.6.

I'm trying to install Garage Band on it. I've gone into the App Store, but when I try to download Garage Band, it says it requires 12.5 or later, which puzzles me.

Any suggestions?

Addendum: I've tried it on a mid-2012 MBP with 16gb ram, 500gb HDD, running Catalina 10.5.7. Now the App Store tells me Garage Band requires 10.13.5 or later. Any workarounds? Might I be doing something wrong?

Thanks