see * https://help.openstreetmap.org/questions/10503/simple-convert-osm-to-kml * https://help.openstreetmap.org/questions/849/how-to-convert-osm-to-kml-format or perhaps https://www.gpsvisualizer.com/gpsbabel/ (if OpenStreetMap data files are indeed the format you downloaded)

see * https://help.openstreetmap.org/questions/10503/simple-convert-osm-to-kml * https://help.openstreetmap.org/questions/849/how-to-convert-osm-to-kml-format or perhaps https://www.gpsvisualizer.com/gpsbabel/ (if OpenStreetMap data files are indeed the format you downloaded)