How to create linux USB discs that do work on Apple Macs?
Check Ubuntu's tutorial how to create a bootable USB stick on macOS, where it is suggested to use Etcher app (open source) which can help to flash OS image to SD cards &amp; USB drives.

However, if the official ISO file downloaded from releases.ubuntu.com doesn't work (for Ubuntu), you can try to customize/respun it by using isorespin.sh script (check GitHub mirror; on macOS, you can try to run it using Docker) which should make your ISO compatible with UEFI. Alternatively, use ready-made Ian Morrison’s ISO disk images.



GitHub project page: resin-io/etcher.