Unable to connect to docker image of postgres

Hi, I follow a tutorial "Laravel Docker Setup" from Tenacity and I have some troubles with connecting to DB. Sorry, forum doesn't allow me to add links to my message.

I copied files from his repo, changed values in .env file, run docker compose up --build --detach and my index page gets this error, I have no idea how to fix it, I'm new to Docker. I have spent f few days but no luck with it.

SQLSTATE[08006] [7] connection to server at "db" (172.18.0.2), port 5432 failed: FATAL: password authentication failed for user "aurum" (Connection: pgsql, SQL: select * from "sessions" where "id" = V4jW7aUlZb7p8P3zHsdZ66OXKyRDti3mMMT6Nrpf limit 1)

Should docker create DB, user with password for me during installation of a project?

When I check "docker logs testapp" (testapp is the name of my postgres container), I see there repeating error

2025-01-02 23:43:16.488 GMT [98] FATAL: password authentication failed for user "aurum" 2025-01-02 23:43:16.488 GMT [98] DETAIL: Role "aurum" does not exist.

Here is my docker-compose.yml

services:
  app:
    build:
      context: ./testapp
      dockerfile: Dockerfile
    restart: unless-stopped
    networks:
        - docker-network
    ports:
      - 9000:9000
    depends_on:
      - db

  queue-worker:
    build:
      context: ./testapp
      dockerfile: Dockerfile
    restart: unless-stopped
    networks:
      - docker-network
    depends_on:
      - db
    command: php artisan queue:work
  
  db:
    image: bitnami/postgresql:16.3.0
    platform: linux/amd64
    container_name: testapp
    ports:
      - 5432:5432
    restart: always
    volumes:
      - db-data:/bitnami/postgresql    
    environment:
      - POSTGRESQL_DATABASE=${POSTGRESQL_DATABASE}
      - POSTGRESQL_USERNAME=${POSTGRESQL_USERNAME}
      - POSTGRESQL_PASSWORD=${POSTGRESQL_PASSWORD}
    networks:
      - docker-network

  caddy:
    image: caddy:latest
    ports:
      - 80:80
      - 443:443
    volumes:
      - ./testapp:/var/www/html
      - ./Caddyfile:/etc/caddy/Caddyfile
    networks:
      - docker-network
    depends_on:
      - app      

  redis:
    image: bitnami/redis:7.2
    platform: linux/amd64
    ports:
      - 6379:6379
    restart: always
    volumes:
      - redis-data:/bitnami/redis/data
    environment:
      - ALLOW_EMPTY_PASSWORD=no
      - REDIS_PASSWORD=${REDIS_PASSWORD}
      - REDIS_DISABLE_COMMANDS=FLUSHDB,FLUSHALL
    networks:
      - docker-network

volumes:
  db-data:
  redis-data:

networks:
  docker-network:
    driver: bridge