502 bad gateway, nginx config looks good

I’m getting 502 bad gateway errors when NGINX config looks good. Can’t seem to figure out what is going wrong.

Here is docker-compose:

version: ‘3’
services:

#PHP Service
app:
build:
context: .
dockerfile: Dockerfile
image: digitalocean.com/php
container_name: digital_ocean_app
restart: unless-stopped
tty: true
environment:
SERVICE_NAME: app
SERVICE_TAGS: dev
working_dir: /var/www
networks:
- app-network

#Nginx Service
webserver:
image: nginx
container_name: nginx-webserver
restart: unless-stopped
tty: true
extra_hosts:
- “my-laravel-social:127.0.0.1”
ports:
- “80:80”
- “443:443”
volumes:
- ./public:/var/www/public
- ./nginx/conf.d/:/etc/nginx/conf.d/
networks:
- app-network

#MySQL Service
db:
image: mysql:5.7.22
container_name: mysql_db
restart: on-failure
tty: true
ports:
- “3306:3306”
environment:
MYSQL_DATABASE: my-laravel-social
MYSQL_ROOT_PASSWORD: trantystrobe
SERVICE_TAGS: dev
SERVICE_NAME: mysql
volumes:
- dbdata:/var/lib/mysql
- ./mysql/my.cnf:/etc/mysql/my.cnf
networks:
- app-network

#Docker Networks
networks:
app-network:
driver: bridge

#Volumes
volumes:
dbdata:
driver: local

Here is NGINX config:

server {
listen 80;
server_name my-laravel-social;
index index.php index.html;
error_log /var/log/nginx/error.log;
access_log /var/log/nginx/access.log;
root /var/www/public;
location ~ .php$ {
try_files uri =404; fastcgi_split_path_info ^(.+\.php)(/.+);
fastcgi_pass mysql_db:9000;
fastcgi_index index.php;
include fastcgi_params;
fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
fastcgi_param PATH_INFO $fastcgi_path_info;
}
location / {
try_files $uri $uri/ /index.php?$query_string;
gzip_static on;
}
}

I’m aware of this, but I do not know why the error is happening

What does the logs say?
Also, where does port 9000 come from?

fastcgi_pass mysql_db:9000;