Thanks, we have also legal access to GTFS of MVG and MVV

https://ptna.openstreetmap.de/gtfs/DE/trips.php?feed=DE-BY-MVV&release_date=&route_id=19-901-s23-21

https://ptna.openstreetmap.de/gtfs/DE/single-trip.php?feed=DE-BY-MVV&release_date=&trip_id=1.T0.19-901-s23-21.3.H