Yeah, I think the developer of Nowhere TV took it down a year or so ago. Lots of the private Roku channel lists you see on the 'net are sadly out of date.
The "channel not available in your region" message appears to be generic error text that is returned when one enters a code for which there is no established channel app. I've entered a nonsense letter combination and received the same error message. The error message is technically correct -- if the code is invalid it does not represent a channel available in that region -- but it is misleading.
For more information on private channels, here's an article on rokuguide.com: https://www.rokuguide.com/private-channels
Roku Community Streaming Expert
I am not a Roku employee, only a user like you. Please, no support questions via private message -- post them publicly to the Community where others may benefit as well.
If this post solves your problem please help others find this answer by clicking "Accept as Solution.".
Streaming Stick 4K+ 3821 | Streaming Stick+ 3810 | TCL Roku TV 43S245/C107X