The DMG file contains a package that installs the "Install macOS Sierra" application into your Applications folder. Double-click InstallMacOSX.dmg to mount it.
Download the macOS Sierra 10.12 dmg directly from Apple Support . download macos sierra 1012 dmg file install
Apple provides a direct download link for older macOS versions, including Sierra 10.12, through their support site. Use Safari for the most reliable download experience. The DMG file contains a package that installs
The DMG file does not install the OS directly; it contains a package that installs the installer app into your Applications folder. including Sierra 10.12
Restart your Mac and hold the key to boot from the USB. Important Compatibility Notes macOS Sierra (10.12.6) Download - Apple Support Community