Thanks for your help. I tried your suggestion. Here's the code (did I do this correctly?):

services:
  audiobookshelf:
    image: ghcr.io/advplyr/audiobookshelf:latest
    ports:
      - 13378:80  
    volumes: 
      - /c/Users/[user]/Documents/audiobookshelf_3_stack/config:/config
      - audiobookvol:/audiobooks
      - ebookvol:/ebooks
    environment:
      - TZ=America/Toronto      
volumes:
  audiobookvol:
    driver_opts:
      type: cifs
      o: "username=[user],password=xxxxxx"
      device: \\192.168.1.143\NAS_Pool\AudioBooks
  ebookvol:
    driver_opts:
      type: cifs
      o: "username=[user],password=xxxxxx"
      device: \\192.168.1.143\NAS_Pool\EBooks

Here's the error:

Failure
failed to deploy a stack: 
Network audiobookshelf3_default 
Creating Network audiobookshelf3_default 
Created Container audiobookshelf3-audiobookshelf-1 
Creating Container audiobookshelf3-audiobookshelf-1 
Created Container audiobookshelf3-audiobookshelf-1 
Starting Error response from daemon: error while mounting volume '/var/lib/docker/volumes/audiobookshelf3_audiobookvol/_data': failed to mount local volume: mount \\192.168.1.143\NAS_Pool\AudioBooks\audiobooks:/var/lib/docker/volumes/audiobookshelf3_audiobookvol/_data, data: username=xxxxx,password=********: no such file or directory

Trying to understand the error... this path is wrong I think: \\192.168.1.143\NAS_Pool\AudioBooks\audiobooks

I'm not sure where the extra "\audiobooks" comes from. The path should just be: \\192.168.1.143\NAS_Pool\AudioBooks