Yep, you can. Came as a surprise to me as well at the time but you definitely can.

You probably got this already if you look ta the Tesseract page and how this all works but I wanted to share with you my docker-compose file to give you an idea how I did it. I find it helpful to look at examples of others sometimes.

Good luck!

# Docker Compose for : Tesseract
# This is a GUI frontend local hosted for Lemmy

services:
  tesseract:
    image: ghcr.io/asimons04/tesseract:latest
    container_name: tesseract
    restart: always
    environment:
      # The domain of Tesseract's 'default' instance. 
      # This is the only required config variable
      - PUBLIC_INSTANCE_URL=feddit.nl
      
      # By default, Tesseract locks itself to the configured instance. 
      # To allow users to add accounts from other instances, set this to false.
      - PUBLIC_LOCK_TO_INSTANCE=false
      
      # Feed, feed sort, and comment sort settings
      - PUBLIC_DEFAULT_FEED=Subscribed
      - PUBLIC_DEFAULT_FEED_SORT=Hot
      - PUBLIC_DEFAULT_COMMENT_SORT=Hot

      # Default to Dark Theme instead of "System"
      - PUBLIC_THEME=System

      # Media Proxying
      # Enable the media proxying module and make it available for use.  
      # It is disabled by default.
      - PUBLIC_ENABLE_MEDIA_PROXY=true
      
      # List of domains that should not be proxied (content reasons, because they won't 
      # work with the proxy, etc)
      - PUBLIC_MEDIA_PROXY_BLACKLIST=mintboard.org,iili.io,img.shields.io
      - PUBLIC_ENABLE_MEDIA_PROXY_LOCAL=true
      
      # Pre-set the "Use media proxy" setting for all users.  
      # If set to false (default), users will need to go into Settings->Media 
      # to enable image proxying.
      - PUBLIC_ENABLE_USER_MEDIA_PROXY=true

      # Media Caching; disabled by default. Enabled and configured here.
      - PUBLIC_ENABLE_MEDIA_CACHE=true
      - PUBLIC_ENABLE_MEDIA_CACHE_LOCAL=true
      - PUBLIC_MEDIA_CACHE_DURATION=4320
      - PUBLIC_MEDIA_CACHE_KEEP_HOT_ITEMS=true
      - PUBLIC_MEDIA_CACHE_MAX_SIZE=500
      - PUBLIC_MEDIA_CACHE_HOUSEKEEP_INTERVAL=5
      - PUBLIC_MEDIA_CACHE_HOUSEKEEP_STARTUP=true
      
      # List of Invidious/Piped domains which should be used for detection. 
      # See docs/CustomYoutubeFrontends.md for more in fo.
      - |-
        PUBLIC_CUSTOM_INVIDIOUS=
          i.devol.it,
          piped.adminforge.de
      
      # List of instances that will be pre-populated into the instance selector on the 
      # community explorer page. 
      # The default instance is included by default and does not need to be listed here.
      - |-
        PUBLIC_FEATURED_INSTANCES=
          lemmy.world,
          mander.xyz,
          programming.dev,
          lemm.ee,
          lemmy.ca,
          lemmy.cafe,
          literature.cafe,
          sh.itjust.works,
          lemmy.blahaj.zone,
          slrpnk.net,
          startrek.website,
          beehaw.org,
          sopuli.xyz,
          lemmy.zip
    
    # Tesseract uses /app/cache inside the container to persist lookups and for the media cache. 
    # This will work without a volume, but anything cached will not persist after the container is restarted.
    
    # Note:  The host directory must be owned by UID/GID 1000.
    volumes:
      - ./cache:/app/cache
    
    # Bind to port 8081 instead of the container's default port of 3000
    ports:
      - 8081:3000