systemd-umount

This command is an alias for systemd-mount --umount.
View documentation for the original command

$ tldr systemd-mount

systemd-umount [options] target...

systemd-umount is an alias for systemd-mount --umount. It unmounts filesystems that were mounted using systemd-mount or transient systemd mount units.
See the systemd-mount documentation for full details on usage and options.

systemd-mount(1), umount(8)