Att lighting to hdmi - DirecTV

I saw another post where someone was trying to get direct tv app to show on a tv using att lighting to hdmi cord. Response said the app won't work with lighting. What will the app work with? Trying to use my iPhone to watch direct tv in an rv. What should I connect it with that will work?

This question, "Att lighting to hdmi," is about DirecTV channels, programming, equipment, and sports.