Follow the instructions to apply the update to your current system. 4. Alternative: macOS Recovery
Yes, but only if you keep it updated. Apple releases periodic security updates for Catalina (though support will eventually end). For banking or sensitive work, consider upgrading to Ventura or Sonoma if your hardware supports it. download macos catalina 10157 dmg file install
Back on the main macOS Utilities window, click and hit Continue. Follow the instructions to apply the update to
Follow the on-screen prompts, accept the software license agreement, and select your primary hard drive. accept the software license agreement