Paste the following command: softwareupdate --fetch-full-installer --full-installer-version 10.15.7
: A Python-based tool available on GitHub that downloads macOS installer files directly from Apple's servers. It can help you obtain the base files needed to create a DMG. Download Macos 10.15 Catalina Dmg File
Visit the Official Apple Support page for older macOS versions. named "Install macOS Catalina.app
Click or Download . The installer, named "Install macOS Catalina.app," will be saved to your Applications folder. 2. Using the Terminal Command Download Macos 10.15 Catalina Dmg File