Because macOS Catalina is no longer the newest version, Apple sometimes hides it from the standard "Software Update" section. The easiest way to get it is via the App Store.
Because High Sierra is an older version, the update might not appear automatically in your "Software Update" menu. Method 1: The Mac App Store (Recommended) how to update macos high sierra 10.13.6 to 10.15
To update from macOS High Sierra 10.13.6 to macOS Catalina 10.15, you typically need to download the installer through the . Unlike newer versions where updates appear in System Preferences, older systems like High Sierra often require a manual download of the major OS installer. 1. Verify Compatibility Because macOS Catalina is no longer the newest
Before starting, confirm your Mac is on the official compatibility list for macOS Catalina: Early 2015 or newer MacBook Air: Mid 2012 or newer MacBook Pro: Mid 2012 or newer Mac mini: Late 2012 or newer iMac: Late 2012 or newer iMac Pro: 2017 or newer Mac Pro: Late 2013 or newer 2. Pre-Upgrade Checklist Method 1: The Mac App Store (Recommended) To