Apple does not provide a direct ISO download. You must first download the "Install macOS High Sierra" application. Official Mac App Store : Use this direct link to macOS High Sierra
hdiutil convert /tmp/HighSierra.dmg -format UDTO -o ~/Desktop/HighSierra.iso Fix the extension: mv ~/Desktop/HighSierra.iso.cdr ~/Desktop/HighSierra.iso 3. Alternative for Windows Users macos high sierra 10.13 6 iso download
: You can find macOS High Sierra in the Mac App Store . Apple does not provide a direct ISO download