Flutter here map navigation edition: how to add label text on marker

Question

I can't find way to add label on marker. I want to add sequence number on marker.

There is no option to add label in marker class.

var ma = MapMarker(GeoCoordinates(m.address?.lat ?? 0, m.address?.long ?? 0), icon);
Metadata metadata = Metadata();
metadata.setString("key_poi", "Metadata: This is a POI.");
ma.metadata = metadata;
hereMapController.mapScene.addMapMarker(ma);