Greeting @kenodave,
Welcome to the Roku Community.
We catch that you are trying to add a channel from the Roku website but receive an error message. Have you confirmed that the device is linked to your Roku account? To check this information, go to Settings > System > About, and from that screen, you will see the Roku account email address linked to the device.
Keep us posted on what you find out and we'll continue to assist you from there.
Regards,
Nimfa