Making an ISO file from an Apple provided DMG file? [duplicate]

I'd like to make a bootable ISO file from Apple-provided DMG file located under Download macOS using Safari on your Mac from: https://support.apple.com/en-us/HT211683. They provide a DMG file with a pkg file inside which I used xar -xf on, leading to a:

• Distribution (exec, 9kb)
• InstallMacOSX.pkg (pkg obviously, 6.21 GB)
• Resources folder (650kb)

I'd assume InstallMacOSX.pkg is the most important, so it has these files:

• Bom
• InstallESD.dmg (6.2 GB)
• PackageInfo
• Payload (9 MB) (Renaming to .zip un'zips' a Install OS X El Capitan.app file)
• Scripts

How would I utilize 'Payload' and 'InstallESD.dmg' to make a bootable ISO file?

Based off of this guide's end results, and my closest OSX version to this, I get these files:

• .fseventsd
• .IABootFiles (24.3 MB)
• .IABootFilesSystemVersion.plist
• .IAPhysicalMedia
• Install macOS Sierra.app (5.03 GB)
• Library
• System (24.3 MB)
• usr

Install macOS Sierra.app has: /Contents/SharedSupport/InstallESD.dmg (5.01 GB).

You can see this post : https://apple.stackexchange.com/a/420325/415185

I think you've only after the last instruction :

mv /tmp/Installer.dmg ~/Desktop

to add :

hdiutil convert ~/Desktop/Installer.dmg -format UDTO -o ~/Desktop/ElCapitan.iso

mv ~/Desktop/ElCapitan.iso.cdr ~/Desktop/ElCapitan.iso

And don't use the last instruction :

sudo asr restore .....