I see Apple TV in the channel store and it says it is "the home of Apple TV+".
Do you see that one?
I'm having a lot of trouble accessing the channel store at all right now - timeouts, forbiddens... So whatever error you get right now might not be long-term.
Hey, @Carolad.
It's great to see you here!
Can you share the Roku device model here so we can take a closer look? (Under Settings > System > About).
We'll try to dive deeper into this.
Roku Community Team
What model Roku do you have. Apple does not support many older ones. You can get the exact model number by going to Settings/System/About.