To generate a Certificate Signing Request using Plesk 12, perform the following steps:
Log in to the Plesk Panel.
Go to the Websites & Domains tab and select the domain to be secured.
Click Secure Your Sites.
Click Add SSL Certificate.
On the next page enter a Certificate Name to easily recognize the certificate. Fill in the required organization information for the CSR:
Country: Select the country from the drop-down list.
State or province: Provide the complete name for the organizations state or region. If not applicable, the city can be used instead.
Location (city): Provide a complete name for the city or locality.
Organization name (company): Provide the legally registered name for the business.
Organization department or division name: Provide the name of division or department within the organization indicated above.
Domain name: Enter the fully qualified domain name for which the SSL will be activated (common name). The common name for Wildcard certificates should be represented with an asterisk in front of the domain (e.g. *.symantec.com).
E-mail: Enter an email address. The email used for CSR generation will not be used for domain control validation or for reception of the issued certificate.
Click on Request.
A new entry will be added to the list of SSL Certificates. Click on the newly created certificate name to see the CSR code and Private Key.
The CSR code will be located at the bottom of the next page. Please include the tags -----BEGIN CERTIFICATE REQUEST----- and -----END CERTIFICATE REQUEST----- when submitting the CSR code for an order.
Once the certificate has been issued, follow the steps from this link to install the certificate on your server.