Thanks for the post.
Regions like the US and UK where Roku directly sells products and services offer an official channel store for available channels/services in those respective regions, based on availability determined by each channel/service provider themselves.
Other locations in which Roku does not officially sell products are unsupported regions; therefore, do not offer the same options for adding channels/services (e.g. Venezuela).
Since Disney+ did not enable the download of their channel on a Roku device in an unsupported region, we would recommend using the direct Disney+ app which normally can be downloaded on mobile devices. In that way, you'll be able to maximize the subscription that you signed up for through them.
We appreciate your understanding.
All the best,
Roku Forum Moderator