Copy an ISO to a USB for an installer on macOS

1. Identify your disk diskutil list

diskutil list

...
/dev/disk2 (external, physical):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:     FDisk_partition_scheme                        *15.5 GB    disk2
   1:                  FAT_32 Untitled                   15.5 GB    disk2s1

Make note of the identifier of the volume. In this case didisk2s1

2. Unmount the volume sudo umount /dev/<IDENTIFIER> (sudo umount /dev/didisk2s1).
3. Convert and copy file sudo dd if=</path/to/image.iso> of=/dev/r<IDENTIFIER> bs=1m (sudo dd⋅if=image.iso⋅of=/dev/rdisk2s1⋅bs=1m")
4. Eject the volume diskutil eject /dev/<IDENTIFIER> (diskutil eject /dev/disk2s1)