With your Roku device in developer mode, you can sideload channels using the Roku web plug-in, and then run sample channels and test and debug your channel application.
The developer must have created their app to be compatible with Roku TV, otherwise you might have to use the Firestick or Android TV and sideload or download from the respective app stores. Also if you have an lg or Samsung, that app is available on the respective smart TV app stores.
Is anyone having trouble looking up your Roku TV IP online so you can add your app into the device .mine kicked my app off I can' no longer search for my IP address