update from 10.12.8 to 10.13

For the strongest security and latest features you'd be advised to upgrade to the newest version of macOS, which at the time of writing is Catalina (10.15). Get it from the App Store, or for more information see How to upgrade to macOS Catalina.

If your Mac is too old to support Catalina, see How to upgrade to macOS High Sierra which includes a special link to find it in the App Store.

Hello Fred,

https://support.apple.com/kb/sp765?locale=en_US

https://itunes.apple.com/app/macos-high-sierra/id1246284741?mt=12