How do I install and use Etcher on Linux for making a live Linux USB?
Did you try looking at the etcher docs? Use your favorite search engine and look for “etcher usb maker”
Just open the Dash and search for the “Startup Disk Creator” application, which is included with Ubuntu. You can also use Etcher to make Bootable USB drives or SD cards. You can checkout the EtcherPC for further information.