SSL certificates rely on a webspace having an exclusive IP address set. However by default, as part of the shared Linux hosting solution your webspace uses a shared IP address. Therefore to use an SSL certificate on your website you need to purchase an exclusive IP address and configure it first.
Purchasing an IP address
Exclusive IP addresses are an optional resource on web hosting service, and if you haven't yet purchased some read this article for assistance in purchasing additional resources first (select "Exclusive IP addresses" during the purchasing process).
Once your order is complete you will be able to follow the steps below.
Configuring your webspace to use an exclusive IP address
To configure your exclusive IP address, login to your control panel and select Websites from the top menu.
Select your website name to continue.
On the websites page, select Web Hosting Settings.
Your current Web Hosting Settings will be shown. You will see that the IP address is Shared. We want to change this to use your exclusive IP address. To do this, select Edit.
Select the dropdown alongside IP address type and set this to Exclusive IPv4. Select Submit to confirm the changes.
You'll now see the IP address listed on this page.