hdiutil unmount /Volumes/Install\ macOS\ Ventura Convert to ISO (hybrid):
This creates Ventura.dmg . Double-click to mount it – it appears as a volume named Ventura . In Terminal: Download Macos Ventura Iso
mv ~/Desktop/Ventura.iso.cdr ~/Desktop/Ventura.iso ISO will be ~12–14 GB. You can zip it: Download Macos Ventura Iso
After download, the installer will be in /Applications/Install macOS Ventura.app Open Disk Utility → File → New Image → Blank Image Download Macos Ventura Iso