is the version most commonly cited as compatible with macOS 10.15.
If you don't have it in your history, sign into your Apple ID on a newer Mac (running Big Sur or later), "get" GarageBand there, then return to your Catalina machine. It will now appear in your Purchased history, allowing the compatible download. garageband catalina 10.15 7 download
Scroll through your list of apps to find GarageBand. Click the Download (cloud) icon. is the version most commonly cited as compatible
: Tools for recording, editing, and mixing tracks into a finished project. "get" GarageBand there