3 free months of Apple Fitness+?

I bought a new iWatch towards the end of 2020. It was marketed that I get 3 months of apple fitness with my purchase. It was not available when I set up my watch. after that it only offered me a 1 month trial every time I would check on the app. I am up do date, and saw an article about resynching the watch with my iPhone, but no luck there. how do I get my 3 free months???