Hi @Anonymous User
Unfortunately with the NowTV App on the YouView boxes you can only watch on demand movies has you have found out.
It's the same with the BT YouView Box that i have.
BT and Sky / Nowtv have agreed a cross platform sharing sometime 2019 where you will be able to watch the nowtv entertainment pass on the BT Youview Box.
The press release hasn't given much information at the moment about if the Talk Talk and retail Youview boxes will be part of the deal agreement.
Obviously this doesn't help you and i can only suggest checking if you own another supported device from the link help guide below.