Where are you located? Not all channels/apps are available in all regions. What's the model number displayed under Settings->System->About? Not all channels/apps are available on all devices.
If you've created a Roku account that is not in your region (e.g., you created a US account and are trying to use it in Latin America), many things won't work properly.
Roku Community Streaming Expert
Help others find this answer and click "Accept as Solution."
If you appreciate my answer, maybe give me a Kudo.
I am not a Roku employee.