how to use dd to make a bootable usb code example

Example 1: ubuntu create bootable usb from iso command line

$ sudo umount /dev/sdb1
$ sudo dd bs=4M if=/home/sana/Downloads/ubuntu-18.04.2-live-server-amd64.iso of=/dev/sdb1 status=progress oflag=sync

dd if=inputfile.img of=/dev/disk<?> bs=4m && sync