Docker image on Google Compute Engine wont run on port 80 - docker

Question

I am deploying my Next.js / Nginx docker image from Container Registry to Compute Engine
Once deployed the application is running as expected, but its running on port 3000 instead of 80 - i.e. I want to access it at <ip_address> but I can only access it on <ip_address>:3000. I have setup a reverse proxy in Nginx to forward port 3000 to 80 but it does not seem to be working.
When I run docker-compose up the app is accessible on localhost (rather than localhost:3000)
Dockerfile
FROM node:alpine as react-build
RUN mkdir -p /usr/src/app
WORKDIR /usr/src/app
COPY package.json /usr/src/app
RUN npm install
RUN npm install --global pm2
COPY . /usr/src/app
RUN npm run build
# EXPOSE 3000
EXPOSE 80
CMD [ "pm2-runtime", "start", "npm", "--", "start" ]
docker-compose.yml
version: '3'
services:
nextjs:
build: ./
nginx:
build: ./nginx
ports:
- 80:80
./nginx/Dockerfile
FROM nginx:alpine
# Remove any existing config files
RUN rm /etc/nginx/conf.d/*
# Copy config files
# *.conf files in "conf.d/" dir get included in main config
COPY ./default.conf /etc/nginx/conf.d/
./nginx/default.conf
proxy_cache_path /var/cache/nginx levels=1:2 keys_zone=STATIC:10m inactive=7d use_temp_path=off;
server {
listen 80;
gzip on;
gzip_proxied any;
gzip_comp_level 4;
gzip_types text/css application/javascript image/svg+xml;
proxy_http_version 1.1;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection 'upgrade';
proxy_set_header Host $host;
proxy_cache_bypass $http_upgrade;
# BUILT ASSETS (E.G. JS BUNDLES)
# Browser cache - max cache headers from Next.js as build id in url
# Server cache - valid forever (cleared after cache "inactive" period)
location /_next/static {
#proxy_cache STATIC;
proxy_pass http://localhost:3000;
}
# STATIC ASSETS (E.G. IMAGES)
# Browser cache - "no-cache" headers from Next.js as no build id in url
# Server cache - refresh regularly in case of changes
location /static {
#proxy_cache STATIC;
proxy_ignore_headers Cache-Control;
proxy_cache_valid 60m;
proxy_pass http://locahost:3000;
}
# DYNAMIC ASSETS - NO CACHE
location / {
proxy_pass http://locahost:3000;
}
}