Create Mac Os X Bootable Usb Installer From Dmg

What you need:

sudo /Applications/Install\ macOS\ High\ Sierra.app/Contents/Resources/createinstallmedia --volume /Volumes/MyVolume --applicationpath /Applications/Install\ macOS\ High\ Sierra.app

Inside the mounted volume, look for one of two things: create mac os x bootable usb installer from dmg

Before you begin: