Where do I add the docker argument for Intel Quick Sync?

[ninjai]

I've tried reading the docs on trunas documentation and I can't find it. I just see I need to add this argument to the docker command:
--device=/dev/dri:/dev/dri

I found this on linuxserver.io:

plex - LinuxServer.io

Welcome to the home of the LinuxServer.io documentation!

docs.linuxserver.io

But I don't know where to add this.

Hardware acceleration users for Intel Quicksync will need to mount their /dev/dri video device inside of the container by passing the following command when running or creating the container:

I tried adding it to "Container Args", but I get:

run/s6/basedir/scripts/rc.init: 67: --device=/dev/dri:/dev/dri: not found

inside the docker logs. My CPU definitely has quick sync, and I'm running the latest stable version of truenas scale.