I cannot launch my php application in browser

Docker Desktop
1

can I ask some help please I want to develop web application using docker nginx,mysql and php
but the problem is when I visit this in url app.dev it says unable to connect. I think my setting are something missing.

docker-compose.yml

version: "3.7"
services:

  webapp:
build: .

  webserver:

image: nginx
container_name: nginx-container
ports:
  - "8080:80"
volumes:
  - ./:/var/www/myapp
  - ./default.conf:/etc/nginx/conf.d/default.conf
links:
  - php
  php:
image: php:7.2-fpm
container_name: php-container


  db:
image: mysql
container_name: mysql-container
command: --default-authentication-plugin=mysql_native_password
volumes:
  - ./mysql-data:/var/lib/mysql
expose:
  - 3306
ports:
  - "3306:3306"
environment:
  MYSQL_ROOT_PASSWORD: rootpass

Dockerfile

FROM php:7.2-cli
COPY . /var/www/myapp
WORKDIR /var/www/myapp

RUN apt-get update && apt-get install -y \
        libfreetype6-dev \
        libjpeg62-turbo-dev \
        libpng-dev \
    && docker-php-ext-install -j$(nproc) iconv \
    && docker-php-ext-configure gd --with-freetype-dir=/usr/include/ --with-jpeg-dir=/usr/include/ \
    && docker-php-ext-install -j$(nproc) gd

cmd [ "php", "./index.php" ]

default.conf

server {
    listen  80;
     index index.php;
     server_name app.dev;
     error_log  /var/log/nginx/error.log;
     access_log /var/log/nginx/access.log;
     root /var/www/myapp;

      location / {
         try_files $uri $uri/ /index.php?$args;
       }

     location ~ \.php$ {
             try_files $uri =404;
             fastcgi_split_path_info ^(.+\.php)(/.+)$;
             fastcgi_index index.php;
             fastcgi_pass php:9000;
             include fastcgi_params;
             fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
             fastcgi_param PATH_INFO $fastcgi_path_info;
         }
 }