I just checked mine..I think its updated so definitely looks different. If you get to your overview with the options on the left, click My Rewards. From there, through the popups, one should say "Visit my Rewards" right in the middle, even though it looks like you have none. That brings you to your dashboard where you'll scroll down and see a bunch of beige targets, one should be "Refer a Friend" ...scroll down to he bottom of the targets and the code should be there. Hopefully that helps!
When your in my referrals, it shows at the top the contest they’re holding right now. Under that it says ‘start referring’. When you click on it, it shows your code that you can copy. ‘Refer-a-friend’ they call it too.