Can't flash rock img to usb stick

Trying to install ROCK on USB stick, but Etcher gives me a message saying something about privileged access. My Mac password doesn’t do it. I’ve never heard about privileged access before, and I’ve never set it up. Any ideas? My hardware is all set(NUC + SSD + Ram), and I have the file from the link on the ROCK install guide.

HELP!

Meant to say IMG not OMG in title

It sounds similar and gives the commands to run etcher properly.