You're going to want to get this project running using Portainer-Stacks. It'll be worth it -- and you'll be better off in the long run for future projects.
It appears from your logs and description that you likely have an issue with the volume you're trying to bind. Which is this section of the docker-compose:
volumes:
- /data/ah4c/scripts:/opt/scripts # pre/stop/bmitune.sh scripts will be stored in this bound host directory under streamer/app
- /data/ah4c/m3u:/opt/m3u # m3u files will be stored here and hosted at http://<hostname or ip>:7654/m3u for use in Channels DVR - Custom Channels settings
- /data/ah4c/adb:/root/.android # Persistent data directory for adb keys
The part to the left of the colon can be whatever you want it to be, and is where your persistent files will be stored on the Docker host (your Synology). The part to the right of the colon are the directories you're mapping to inside the container -- these are not to be changed.
Since you're likely not running Docker or Portainer as root, you'll need to be sure the directories you're mapping to are ones that your "user" can access. Choose a base directory that works for you on the host, for example I use /data/ah4c, and then scripts, m3u and adb will be created for me under that base.
EDIT: Follow the same basic structure though, specifying paths that have scripts, m3u and adb as the final sub-directories, and group them under a directory called ah4c. What you have as a parent directory to ah4c is whatever works for you.