
You may prefer to use one of the
official docker containers. The containers will work on any standard Linux system that supports containers. I don't have instructions for True NAS Scale specifically but the WebUI for docker containers will almost certainly
look like the one on unRAID since they usually are just thin wrappers for the
docker command-line tool.

That said, if it's a standard Linux system, then you can use the
How do I manually install FileBot on Linux / BSD / Solaris / any Unix OS? instructions as well. I don't know if TrueNAS gives you easy SSH access like a normal Linux system would though.

If you're new to FileBot, then I strongly recommend just using the FileBot Desktop application from your Desktop PC and then renaming files remotely via a network share.