: Click the Get or Download button. This will often open the "Software Update" pane in System Preferences.
: macOS Catalina 10.15.2 Combo Update from Apple Support. File Size : Approximately 4.59 GB . macOS Catalina 10.15.2 Free Download
: Visit the official macOS Catalina page on the Mac App Store . : Click the Get or Download button
If you are and just want to update specifically to 10.15.2, you can use the standalone installer. macOS Catalina 10.15.2 Free Download
This is the best method if you are upgrading from an older macOS (like Mojave) or need to create a bootable installer.