Billing usage was specified during channel publishing but was not found in BrightScript code

If you intend to handle in channel billing for a screensaver you will need to add a "RunScreenSaverSettings" entry point.  This will available on the system screensaver chooser. Otherwise if you want the channel to be a one time purchase, just set it in the dev portal monitization option.

https://developer.roku.com/en-us/docs/developer-program/media-playback/screensavers.md