Empty volume directory

Hello.
I have a docker-compose script. After launching it, the files do not appear in the required directories, but project run successful. But if I create files in /app/backend before start containers, I can see a vendor dir with installed packages.
How to fix it?

version: '3.7'
networks:
  frontend:
    driver: bridge
    ipam:
      config:
        - subnet: 10.5.0.0/16
  backend:
    driver: bridge
    ipam:
     config:
       - subnet: 10.6.0.0/16
services:
  php:
    build:
      context: .
      dockerfile: .docker/php-dockerfile
    container_name: myapp-php
    ports:
      - 9000:9000
    volumes:
      - ./app/backend:/var/www/backend
      - ./app/logs:/var/www/logs
    networks:
      backend:
        ipv4_address: 10.6.0.3
  nginx:
    build:
      context: .
      dockerfile: .docker/nginx-dockerfile
    container_name: myapp-nginx
    restart: unless-stopped
    ports:
      - 80:80
    volumes:
      - ./app/backend:/var/www/backend
      - .docker/config/nginx:/etc/nginx/conf.d/
      - ./app/logs/nginx:/var/log/nginx
    depends_on:
      - php
    networks:
      backend:
        ipv4_address: 10.6.0.5
  composer:
    build:
      context: .
      dockerfile: .docker/composer-dockerfile
    container_name: myapp-composer
    command: composer install
    depends_on:
      - php
    volumes:
      - ./app/backend:/var/www/backend
    networks:
      backend:
        ipv4_address: 10.6.0.6
  app:
    build:
      context: .
      dockerfile: .docker/node-dockerfile
    container_name: myapp-node
    command: npm run dev
    environment: 
      NODE_ENV: production
    working_dir: /var/www/html
    ports:
      - 443:443
    volumes:
      - ./app/frontend:/var/www/html
    depends_on:
      - php
    networks:
      backend:
        ipv4_address: 10.6.0.2
      frontend:
        ipv4_address: 10.5.0.2