CSR code has to be generated on side of the company that provides hosting services for site that you want to secure with SSL certificate. Which means that your hosting company is the one that should generate CSR code upon your request.
If you decide to generate CSR code yourself or if your hosting company advises you to do so, then please follow CSR generation instructions provided by Certification Authorities. Click on name of certificate that you would like to activate to get to article on generation CSR code for it.