Autoscan

Your first step, before even running the tag, is to create a config file at:

/opt/autoscan/config.yml

You can find details on creating the config file in the autoscan readme

A minimal config file could be something like this, assuming no path rewrites are required:

 anchors:
  - /mnt/unionfs/drive1.anchor

triggers:
  sonarr:
    - name: sonarr
  radarr:
    - name: radarr

targets:
  plex:
    - url: https://plex.domain.tld # URL of your Plex server
      token: XXXX # Plex API Token

Once you've created the config file, run the tag.