For Windows, the installer puts the app icon in the start menu only. Use the start menu or search and it comes up.
For MacOS, it depend on where you drag the app out of the DMG but usually it is /Applications in Finder. The executable is then /Applications/Shotcut.app/Contents/MacOS/shotcut per the app nimble standard.
For Linux, it depends very much on which app package you used and the distribution.