07-04-2018 9:34 AM
So - to sum up: The service's technology doesn't currently support 4K - that is reportedly going to change later this year - so even if there was 4K content, they couldn't sent it to you. And there is no 4K content - currently none of the content providers they offer provides anything in 4K. That is likely to start changing (slowly) over the next year or two.
07-04-2018 10:36 AM
You won't find any 4K on DTVN, or most cable or satellite systems either, or any OTT streaming service I'm aware of.
Assuming your streaming device and your TV set support it, try searching the app store for whatever device you are using for 4K channels. Netflix has some 4K offerings. Be aware you will need more internet speed than standard HD requires.