Trying to setup this dockerhub/github image in Unraid

I'm going to assume this falls under "I still don't really know what I'm doing," but here's my issue:

I'm trying to set up this docker image in Unraid 7.

https://hub.docker.com/r/starkayc/orpheusbetter

https://github.com/starkayc/orpheusbetter-crawler

(those links are both to the same project).

I went into the Docker tab and added a new container. I put starkayc/orpheusbetter:latest as the Repository

I added paths for config, data, torrent, app

Extra parameters: starkayc/orpheusbetter -c "/app/orpheusbetter --threads 4"

Here's what Unraid ran:

docker run
  -d
  --name='OrpheusBetter'
  --net='bridge'
  --pids-limit 2048
  -e TZ="America/New_York"
  -e HOST_OS="Unraid"
  -e HOST_HOSTNAME="Unraid"
  -e HOST_CONTAINERNAME="OrpheusBetter"
  -l net.unraid.docker.managed=dockerman
  -v '/mnt/user/appdata/orpheusbetter/':'/config/.orpheusbetter':'rw'
  -v '/mnt/user/orpheusbetter/data':'/data':'rw'
  -v '/mnt/user/orpheusbetter/torrent':'/torrent':'rw'
  -v '/mnt/user/orpheusbetter/':'/app':'rw' starkayc/orpheusbetter
  -c "/app/orpheusbetter
  --threads 4" 'starkayc/orpheusbetter:latest' 

This "finished successfully" but when I check the log it just says:

starkayc/orpheusbetter:latest: line 0: /app/orpheusbetter: not found

And that's where I'm stuck. Whenever I run the docker image, it just spits out that line, and stops.

Again, I assume this is a "I don't know enough" problem. Can anyone point me in the right direction?

It seems like it's not doing all the setup its supposed to do? Downloading python packages and whatnot?