I am running my react app on nginx server via Docker.

Without docker and nginx, my app runs fine on localhost:3000/app path.
But After adding Dockerfile and nginx, it is redirecting the path to localhost/app, ignoring the port.

Dockerfile

FROM node:16 as build
 
WORKDIR /app
 
COPY package*.json ./
 
RUN npm install
 
COPY . .
 
RUN npm run build
 
FROM nginx:alpine
 
RUN rm -rf /etc/nginx/conf.d/*
 
COPY nginx.conf /etc/nginx/conf.d/default.conf
 
COPY --from=build /app/build /usr/share/nginx/html/app
 
EXPOSE 80
 
CMD ["nginx", "-g", "daemon off;"]

nginx.conf

server {    
    listen 80;    
    server_name localhost;    
    location /app{        
        alias /usr/share/nginx/html;        
        try_files $uri $uri/ /index.html;    
    }
}

Below is the command, I am running for docker app
docker run -p 3000:80 app

I have tried multiple approaches for nginx.conf file and Dockerfile.
But nothing seems to work.

I am new to react and dockerfile, I feel that there is just a small piece of the puzzle which I am missing.
Any help will be appreciated.