https://www.digitalocean.com/community/tutorials/initial-server-setup-with-ubuntu-18-04 https://www.digitalocean.com/community/tutorials/how-to-install-nginx-on-ubuntu-18-04 https://www.digitalocean.com/community/tutorials/how-to-secure-nginx-with-let-s-encrypt-on-ubuntu-18-04 https://www.digitalocean.com/community/tutorials/how-to-set-up-a-node-js-application-for-production-on-ubuntu-18-04

https://developer.mozilla.org/en-US/docs/Learn/Server-side/Express_Nodejs/deployment

Edit the /etc/environment file: Add NODE_ENV=production to a new line