https://apple.stackexchange.com/questions/94330/how-can-i-convert-a-dmg-to-iso-on-mac-os-x-preferably-for-free
hdiutil makehybrid -iso -joliet -o [filename].iso [filename].dmg
Renaming .cdr to .iso is bad advice! An .iso has a slightly different format that allows PC users to play the DVD as well. A renamed file will work on macOS, but NOT on a PC.
hdiutil makehybrid -iso -joliet -o [filename].iso [filename].cdr
Can't loaded on Windows 11.
Convert DMG to CDR or ISO with Disk Utility