My compose:

services:
  termix:
    image: ghcr.io/lukegus/termix:latest
    container_name: termix
    restart: unless-stopped
    ports:
      - 8081:8081
    volumes:
      - /home/dockervolumes/data:/app/data
    environment:
      PORT: "8081"
volumes:
  termix-data:
    driver: local
networks: {}

It works great.

Adding hosts is currently only possible in a browser, not on a smartphone.

Yes