If you are already on a newer version of macOS, you can often "fetch" the full installer by pasting this into your Terminal : softwareupdate --fetch-full-installer --full-installer-version 10.13.6
Before downloading, ensure your hardware is compatible. High Sierra generally requires at least and 14.3GB of storage . Supported Mac Models: MacBook: Late 2009 or newer MacBook Pro: Mid 2010 or newer MacBook Air: Late 2010 or newer Mac mini: Mid 2010 or newer iMac: Late 2009 or newer Mac Pro: Mid 2010 or newer 3. How to Create a Bootable USB Installer Macos High Sierra 10.13.6 Raw Download
This guide provides everything you need to safely find the and create a bootable installer. 1. Official macOS High Sierra Download Links If you are already on a newer version
Enter your admin password when prompted. The process will take 15–30 minutes. How to Create a Bootable USB Installer This
The safest way to get the "raw" installer files is directly through Apple's infrastructure to avoid malware or corrupted data.
I need to get macOS High Sierra dmg file… - Apple Community