Strapi page shows as Development before login

I have successfully installed and deployed strapi to production. Using this guide

My doubt is, I see this Development word if I visit the Strapi homepage. But .com/admin is a normal login screen.

Whether I installed correctly or made any mistake so it’s showing like this?

System Information
  • Strapi Version: v4.0.2
  • Operating System: Ubuntu 20.04
  • Database: MySQL
  • Node Version: v16.13.1
  • NPM Version: 8.1.2
  • Yarn Version: 1.22.17

I’m using pm2 so running this command helped.

NODE_ENV=production pm2 start server.js