There are two ways to do this: one with third party software, and another with the Terminal. Again, the installer will launch when the download is complete close the window when this happens. Click the “Download” button to the left of the release you want to install, and your Mac will download it. You will only find versions you’ve previously downloaded here. Instead, you’ll have to head to the “Purchases” tab in the installer and scroll down until you find the version of macOS you want on your thumb drive. If you don’t want the latest version of macOS, searching the App Store won’t help you.
