You can either let UNetbootin download one of the many distributions supported out-of-the-box for you, or supply your own Linux.ISO file. The application is cross-platform and is available for Windows, Linux, and Mac OS X. UNetbootin allows you to create bootable Live USB drives for Ubuntu, Fedora, and other Linux distributions without burning a CD. UNetbootin is a free, open-source utility that allows you to create bootable USB drives on Windows, Linux, and Mac OS X. But the easiest way to create Windows 10 bootable USB is using third-party software like UNetbottin. To create Windows 10 bootable USB on macOS Mojave and macOS Catalina using Boot Camp Assistant isn’t supported anymore.
How to Create a Windows 10 Bootable USB on Mac High Sierra Create Windows 10 Bootable USB on Mac Using UNetbottin