Did you saw a notification into your booking online ? You will get a fly option but you will need to confirm it, if you havent, go to your online booking and go to the banner that says confirm your new fly, in the bottom you will see that the you can choose more fly options.
If not, seen me a private with your booking number and i can change it for your, for Latam Platinum or more you have another contact center that is quitte better.