I want to run simple php with frankenphp inside docker - Stack Overflow

I want to run my simple PHP script. like return phpinfo() with frankenphp inside docker. But I have a problem for this simple script. Always not resolve when accessing localhost:8080.

This my Dockerfile

FROM dunglas/frankenphp:latest

RUN apt-get update && apt-get install -y \
    git \
    unzip \
    vim \
    && rm -rf /var/lib/apt/lists/*

WORKDIR /var/www/public_html

COPY ./app .

EXPOSE 80

CMD ["frankenphp", "php-server", "-r", "/var/www/public_html"]

and this my docker-compose

version: '3.8'
services:
  app:
    container_name: therapy_app
    build:
      context: .
      dockerfile: Dockerfile
    ports:
      - "8080:80"
    volumes:
      - ./app:/var/www/public_html
    environment:
      - APP_ENV=local
      - APP_DEBUG=true
    networks:
        - therapy_nt

networks:
    therapy_nt:
      driver: bridge

This my index.php file

<?php
phpinfo();

after I run docker compose up -d succeeded running the container. But, when I access localhost:8080 it doesn't work.

Folder structure :

- app
  + index.php
- Dockerfile
- docker-compose.yml 

Is there something missing from my steps?