proxy:error] [pid 137137] (111)Connection refused: AH00957: HTTP: attempt to connect to ip:49000

My site was running fine and then I updated nuxt.config.js. Then after that, the site starts to show Service Unavailable.

I am using pm2 to start / deploy the app. Its vps server with apache in it.

Its showing:

Service Unavailable
The server is temporarily unable to service your request due to maintenance downtime or capacity problems. Please try again later.

But, if I run npm run dev the site loads fine without any issue. Also, I checked the status with pm2 list, it showing the app is online.

My package.json

{
  "name": "nuxtjs",
  "version": "1.0.0",
  "private": true,
  "scripts": {
    "dev": "nuxt --hostname domain.link --port 49000",
    "build": "nuxt build",
    "start": "nuxt start",
    "generate": "nuxt generate",
    "deploy": "pm2 start npm --name nuxtjs -- start"
  },
  "dependencies": {
    "@nuxtjs/axios": "^5.13.6",
    "@yeger/vue-masonry-wall": "^3.0.16",
    "core-js": "^3.19.3",
    "nuxt": "^2.15.8",
    "pm2": "^5.1.2",
    "vue": "^2.6.14",
    "vue-server-renderer": "^2.6.14",
    "vue-template-compiler": "^2.6.14",
    "webpack": "^4.46.0"
  },
  "devDependencies": {},
  "config": {
    "nuxt": {
      "host": "0.0.0.0",
      "port": "49000"
    }
  }
}

And, my domain.link.conf looks like:

<VirtualHost *:80>

    ServerName domain.link
    ServerAlias www.domain.link
    ServerAdmin admin@domain.link

    DocumentRoot /var/www/html
    <Directory /var/www/html/>
        Options Indexes FollowSymLinks MultiViews
        AllowOverride All
        Require all granted
    </Directory>

    ProxyRequests Off
    ProxyPreserveHost On
    ProxyVia Full

    <Proxy *>
        Require all granted
    </Proxy>

    ProxyPass / http://domain.link:49000/
    ProxyPassReverse / http://domain.link:49000/

    ErrorLog ${APACHE_LOG_DIR}/error.log
    CustomLog ${APACHE_LOG_DIR}/access.log combined

</VirtualHost>

But, if I check apache2/error.log it showing:

[Sun Feb 06 09:15:31.555004 2022] [proxy:error] [pid 137137] (111)Connection refused: AH00957: HTTP: attempt to connect to ip:49000 (domain.link) failed
[Sun Feb 06 09:15:31.555068 2022] [proxy_http:error] [pid 137137] [client 27.34.104.213:56874] AH01114: HTTP: failed to make connection to backend: domain.link, referer: http://domain.link/