Welcome! This app probably organizes the JSON differently, so it would have to be migrated before it can be imported in SeriesGuide.
See JSON export format · UweTrottmann/SeriesGuide Wiki · GitHub for the current format. Though note that this is currently changing due to the TMDb migration. E.g. if you are on SeriesGuide 58 or higher, just add a test show and export that to see the current format.
More links: