How to play Body FX workouts on your Fire TV. Download the Body FX app by searching for Body FX in the Amazon search field. Once downloaded, open the Body FX app and select any of your purchased workouts or subscription videos. Click ‘Watch Now’ and log in with your username and password. Click ‘Watch Now’ again and your video will play. You can play any of your purchased or subscription videos from the Body FX app. If you would like to subscribe or purchase additional videos, please visit access.bodyfx.com or email [email protected] for assistance.