On Windows, you'll want to go with the "Eject this device safely" USB thingy in the status bar.
On macOS, with a right click > Eject on the volume's icon on the desktop (or the Eject button below it in Finder).
(Replace that with the actual proper name of those things, because I'm not running either of those right now ^^)
On Linux, via the
eject command
.