The following steps is an example of how you can use your Mac to put a Linux ISO image on a USB stick and then use it to boot a computer to install Linux on it.
$ hdiutil convert -format UDRW -o ubuntu-19.04-desktop-amd64.img ubuntu-19.04-desktop-amd64.iso $ mv ubuntu-19.04-desktop-amd64.img.dmg ubuntu-19.04-desktop-amd64.img $ diskutil list $ diskutil unmountDisk /dev/disk2 $ sudo dd if=ubuntu-19.04-desktop-amd64.img of=/dev/rdisk2 bs=1m