Roku does not create the channel apps that run on it, the channel providers do. Roku just provides the platform on which they run. I expect the situation is the same with Apple TV.
If the Church Webcast system has not created these platform-specific channel apps, then the only option I know of is to cast from a device that can receive their webcasts to the Roku or Apple TV.
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.".
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