Hype is known to be an HTML output app it wasn't meant be used as a full-fledged motion design app even though sometimes people like myself actually use it like a motion design app to export videos. That said, Hype is not like Apple Motion or After Effects that has alpha channel support on export. There's a bit of an obvious workaround to this, you can put a moving background or video and export it as a final video output.
Alpha Channel Support has been requested see thread below.