How to get old versions of macOS
https://support.apple.com/en-us/HT211683
How to get old versions of macOS
If your Mac isn't compatible with the latest macOS, you might still be able to upgrade to an earlier macOS, such as macOS Catalina, Mojave, High Sierra, Sierra, or El Capitan.
To get the latest features and maintain the security, stability, compatibility, and performance of your Mac, it's important to keep your software up to date (https://support.apple.com/kb/HT201541). Apple recommends that you always use the late...