If your Mac is on a newer OS, it may block the download. In this case, use Method 2 or 3. Method 2: Use Terminal (The Professional Way)
Click Get . The "Software Update" window will open. Confirm the download (approx. 8GB). download macos catalina 10157 dmg file better
The final build. The last, most stable version of 10.15.7. The one that fixed the Time Machine bug and the USB-C handshake issue. She’d gotten lucky. If your Mac is on a newer OS, it may block the download