Your DVR should show a message confirming the activation.
iHeart Radio doesn't appear in my Music & Photos list:
Premiere Series DVRs only:
iHeart Radio requires that you use the high-definition TiVo menu (HDUI). The launch point will not display in the classic standard definition menu (SDUI). If you aren't sure which menu type you are using, go to: How to Set the Video Output Format on Your DVR