Replace /Volumes/Untitled with the name of your USB drive.
Unfortunately, Apple doesn't provide a direct download link for macOS Catalina ISO files. However, you can use the following method to create a bootable installer: descargar macos catalina iso espa%C3%B1ol apple
Keep in mind that creating an ISO file might not be the recommended approach, as it may not be compatible with all systems or bootable. Replace /Volumes/Untitled with the name of your USB drive