: Older macOS versions are often hidden or completely unavailable on newer Macs through the traditional App Store interface.
sudo /Applications/Install\ OS\ X\ El\ Capitan.app/Contents/Resources/createinstallmedia --volume /Volumes/MyVolume --applicationpath /Applications/Install\ OS\ X\ El\ Capitan.app Mac Os X El Capitan 10.11.6 Installer Dmg Download
Verifying integrity
When you download El Capitan from Apple, you do not receive a standard app file. Instead, you download a disk image containing an installation package. You must extract this package to use it. : Older macOS versions are often hidden or