Updating or reverting MacOS on a 2020 Intel iMac
Updating or reverting MacOS on a 2020 Intel iMac
You can’t install macOS versions older than the one that came with your Mac. The 2020 update, Big Sur, is the latest release. If your software doesn’t work on Big Sur, it won’t run on any of those Macs, and you’ll need to try other devices. Catalina could work, but it’s too outdated for the required app support.