How to use load balancer domain name for NGINX upstream backend server

upstream source {
   server 192.168.28.129:80 weight=1 max_fails=2 fail_timeout=30s;
   server 192.168.28.130:80 weight=1 max_fails=2 fail_timeout=30s;
}

server {
        listen       80;
        server_name  down1.example.com;
        location /source {
           root html;
           index index.html index.htm;
           proxy_pass http://source/;
           proxy_set_header Host $host;
           proxy_set_header Cookie $http_cookie;
           proxy_set_header X-Real-IP $remote_addr;
           proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
           proxy_set_header X-Forwarded-Proto $scheme;
           client_max_body_size 300m;
        }
}

192.168.28.129 , 192.168.28.130 the download address of the IP, for the two downloaders is now 192.168.28.129 , 130 how to make these two IP domain names

Mar.23,2021

modify your local host file to add corresponding dns parsing

linux/etc/hosts
windowsC:\Windows\System32\drivers\etc\hosts

IP example.com
Menu