Can't change Dgraph Zero URL in Ratel

I have run this compose

# This Docker Compose file can be used to quickly bootup Dgraph Zero
# and Alpha in different Docker containers.

# It mounts /tmp/data on the host machine to /dgraph within the
# container. You can change /tmp/data to a more appropriate location.
# Run `docker-compose up` to start Dgraph.

version: "3.2"
services:
  zero:
    image: dgraph/dgraph:v21.03.1-8-g7f51327fd
    volumes:
      - /dgraph
    ports:
      - 5080:5080
      - 6080:6080
    restart: on-failure
    command: dgraph zero --my=zero:5080
  alpha:
    image: dgraph/dgraph:master
    volumes:
      - /dgraph
    ports:
      - 8080:8080
      - 9080:9080
    restart: on-failure
    command: bash -c "
             echo '12345678901234567890123456789012' > hmac_secret_file &&
             dgraph alpha --my=alpha:7080 --zero=zero:5080 --acl secret-file="./hmac_secret_file" --security whitelist="10.0.0.0/8,172.0.0.0/8,192.168.0.0/16"
             "
  ratel:
    image: dgraph/ratel:latest
    ports:
      - 8000:8000
    command: dgraph-ratel

And it is running just fine with the latest Ratel build.