Docker Swarm – communicate between two containers?

I created docker-compose.yml which works on my computer (local) but not work on server (docker swarm, portainer). Container nginx can`t see php-fpm.

docker-compose.yml:

version: "3"

services:
  nginx:
    image: nginx-php-test:8
    ports:
    - "8888:80"
    restart: always
    environment:
    - ROLE=nginx #run nginx

  fpm:
    image: nginx-php-test:8
    environment:
    - ROLE=fpm #run php
    restart: always

in /etc/nginx/conf.d/default:

...
fastcgi_pass fpm:9000;
...

and entrypoint.sh for nginx-php-test:

#!/bin/bash

if [ "$ROLE" == "nginx" ]; then
    exec /usr/sbin/nginx
elif [ "$ROLE" == "fpm" ]; then
    exec /usr/sbin/php-fpm7.4 -F
fi

How to connect to the fpm container?

Source: StackOverflow