The Fire TV voice search feature is provided by Amazon. It works well to search for features or apps available on the Fire TV, but the ability to search for a specific channel within the app you use for cable streaming services will be limited.  As of June 30, 2020, only Sling offers channel guide integration. If you try to search for a channel using voice search, and you do not have Sling as your provider, the search results will likely be the app for that channel and not the actual channel itself.  Trying to use this app (vs your cable streaming service) will result in the app asking you who your service provider is, and none of the streaming services are service providers that work for this purpose. (Please note: StreamWise Solutions is not a service provider and cannot be used as one to watch the channel through the app.) Instead, you'll have to manually look for the channel within your cable streaming service app when you want to watch a specific channel.