"There is no operating system installed in this virtual machine." using "img" file

Hello. I'm trying to get ParrotOS to work. For some reason the arm64 distribution uses the "img" format, which may or may not be why I get the error. I attempted to convert to iso using hdiutil but I get the same error. For what it's worth, both image formats mount in OS X just fine.

The image is available here:
https://download.parrot.sh/parrot/iso/5.1/Parrot-security-rpi-5.1_arm64.img.xz
(I decompressed using xz -d)

My attempt at making an iso:
hdiutil convert Parrot-security-rpi-5.1_arm64.img -format UDTO -o Parrot-security-rpi-5.1_arm64.iso

Any suggestions?