Roku has removed support for all private channels. If it's not available in the Roku Channel Store, it can't be installed and any existing installations were removed.
I just checked the channel store, and his channel is now available there. It can be installed for free, but requires a direct subscription for full access to all content. They don't list any geographical restrictions, but I wouldn't be surprised if it's only available within the US. You'd have to contact the channel provider. From what I can see on their web site, there's nothing specific about where it's available and what model Roku devices are supported. You would need to contact them for the specifics.
I am brand new and added the app through my roku. Took 30 seconds and works fine.