Install Parrot OS on external drive from macOS

Hello,
I would like to install Parrot OS on a external ssd from my macbook pro. I don’t really want to have dual boot on my laptop just I would like to have on a external drive.

I was looking on the internet how I can do but I can’t find any useful information.

I have a ssd 256 GB and I would like to install the .iso file from my macbook pro (catalina).