How to solve [Undefined index: name] in Laravel-docker

I am trying to execute Laravel with docker on Ubuntu 20.04 At first, I installed docker and created docker-compose.yml so on.

version: "3.7"
services:
  app:
    build:
      args:
        user: sammy
        uid: 1000
      context: ./
      dockerfile: Dockerfile
    image: travellist
    container_name: travellist-app
    restart: unless-stopped
    working_dir: /var/www/
    volumes:
      - ./:/var/www
    networks:
      - travellist

  db:
    image: mysql:5.7
    container_name: travellist-db
    restart: unless-stopped
    environment:
      MYSQL_DATABASE: ${DB_DATABASE}
      MYSQL_ROOT_PASSWORD: ${DB_PASSWORD}
      MYSQL_PASSWORD: ${DB_PASSWORD}
      MYSQL_USER: ${DB_USERNAME}
      SERVICE_TAGS: dev
      SERVICE_NAME: mysql
    volumes:
      - ./docker-compose/mysql:/docker-entrypoint-initdb.d
    networks:
      - travellist

  nginx:
    image: nginx:alpine
    container_name: travellist-nginx
    restart: unless-stopped
    ports:
      - 8000:80
    volumes:
      - ./:/var/www
      - ./docker-compose/nginx:/etc/nginx/conf.d/
    networks:
      - travellist

networks:
  travellist:
    driver: bridge

docker-compose exec app composer install

Generating optimized autoload files
> Illuminate\Foundation\ComposerScripts::postAutoloadDump
> @php artisan package:discover --ansi

In PackageManifest.php line 122:
                         
  Undefined index: name  
                         

Script @php artisan package:discover --ansi handling the post-autoload-dump event returned with error code 1

when I entered this command, I have got some error "undefined index: name"

If you can solve this error, please let me know.

Thanks.