How to generate a CSR code using OpenSSL (Apache, Nginx, etc)

To obtain an SSL Certificate, it is first necessary to generate and submit a Certificate Signing Request (CSR) code to the Certificate Authority (or an SSL vendor). How do I create a CSR file in OpenSSL?

This short guide explains how to generate a CSR code using the OpenSSL utility on a GNU-Linux-based server (Ubuntu, CentOS, etc). The instructions are applicable if you run such well-known web servers like Apache and NGINX, or other mail/app servers like Postfix/Dovecot.

The command in the video is:

When the CSR is generated, send it to your SSL provider to proceed with SSL activation.