Docker4Drupal uses traefik container for routing. By default, we use port 8000 to avoid potential conflicts but if port 80 is free on your host machine just replace traefik's ports definition in the compose file.
You can modify domains under labels definition, e.g.
traefik.frontend.rule=Host:mailhog.drupal.docker.localhost. Note: if domains end with
docker.localhost you don't need to add records to /etc/hosts file
IMPORTANT: you might need to add *.docker.localhost domains manually to your /etc/hosts file