I have signed up and activated my Discovery+ account and I can watch it on my iPad. How do I watch it on my TV through my BT TV 4K box as there seems to be no app. I have tried it by mirroring it from my iPad but whilst the Discovery+ home page appears on the TV screen as soon as you try to play something on the app, the picture on the TV screen disappears. As my box is only 3 months old I presume it’s the latest version