If the App Store says your Mac is incompatible, your hardware likely cannot run Catalina smoothly anyway. Stick with High Sierra or Mojave for very old machines.
The information here aims to guide you through safe practices for obtaining and installing macOS updates. mac os catalina 1015 7 dmg download free
[Free Download] macOS Catalina 10.15.7 DMG Installer (Official) If the App Store says your Mac is
:The most reliable way to get the full installer is through the macOS Catalina App Store link . Clicking Get will open System Preferences or Software Update to begin the download. mac os catalina 1015 7 dmg download free