Hi @a1jonuk. Welcome to GoDaddy Community! Your free SSL Certificate should be available in your account automatically. You can use the instructions here to request it. If you're not seeing the option to do this, I'd recommend getting in touch with our customer care team so they can determine what's happening.
JesseW - GoDaddy | Community Manager | 24/7 support available at x.co/247support | Remember to choose a solution and give kudos.
In case you didn't pay for a year up front: I had the same issue and just called support. I was told that you have to pay for a full year to get the SSL certificate for free for 1 year, which I did not do. I do not recall seeing that condition specified in the renewal/upgrade process.