Here's my podman-compose.yml file (you can use this as you docker-compose file as well):

version: "3"

services:
  languagetool:
    image: erikvl87/languagetool:latest
    container_name: languagetool
    ports:
        - 8010:8010  # Using default port from the image
    environment:
        - langtool_languageModel=/ngrams  # OPTIONAL: Using ngrams data
        - Java_Xms=512m  # OPTIONAL: Setting a minimal Java heap size of 512 mib
        - Java_Xmx=1g  # OPTIONAL: Setting a maximum Java heap size of 1 Gib
    volumes:
        - path/to/ngrams:/ngrams
    restart: always

Just download the ngrams from this link and change the path in the file. You can use this with a Firefox or Thunderbird addon. Go to the advanced settings in the addon preferences and add http(s)://YOUR_IP_OR_DOMAIN/v2 in the other server option.

References:

• https://github.com/Erikvl87/docker-languagetool
• https://dev.languagetool.org/finding-errors-using-n-gram-data
• https://dev.languagetool.org/http-server