Yep send it back and get a firestick. There are paid subscription apps for roku disney+ and the likes not sure if britbox is on there yet. Kids have one in the bedroom and use plex to access our video library and also disney+
I'm disappointed with my Roku. Bought it from Amazon (I know, I know) and it doesn't even have a Prime Video app. It plays Netflix and YouTube with all the ads and that's it.