Need Garageband for Catalina

I just upgraded a 2016 iMac, reluctantly, from Mojave to Catalina to solve an iCloud connection issue on the advice of an Apple Tech. So I have to purchase new versions of several apps. But I can't use the current version of Garageband! It needs Big Sur. I don't want to buy a new version of Parallels and who knows how many other apps that won't run on Big Sur. I'm sure there must be the previous version of Garageband somewhere in the Apple system - how do I download it? All I want is the APPLE app that is compatible with my currently-supported APPLE operating system. Is that too much to ask?