Nginx In Docker: location config not working

Attaching docker File.

FROM nginx:1.17.4-alpine

# copy artifact build from the 'build environment'
COPY ./dist /usr/share/nginx/html/
COPY ./default.conf /etc/nginx/conf.d/
# expose port 4202
EXPOSE 80

# run nginx
CMD ["nginx", "-g", "daemon off;"]

The nginx config(default.conf) is shown below

server {
    listen       80;
    server_name  localhost;

    location / {     
        root   /usr/share/nginx/html/;
        index  index.html index.htm;
    }

    location /site {
        alias   /usr/share/nginx/html;
        index  index.html;  
    }

}

I successfully built and executed docker container using docker run -p 4202:80 imageprocessor:v1

But whenever I try to browse localhost:4203/site, it is redirecting to localhost/site

Why is this happening? Please help.

Source: StackOverflow