how to add labels to geojson layer in google maps

I have a polygon layer geojson that show the states of the US. I use this layer on a google maps (using the google maps js api).

I can get the polygons to display, but I want to set labels on each state. How do I add the labels to the state?

here’s my code:

map = new google.maps.Map(document.getElementById('map'), {
  center: {lat: latitude, lng: longitude},
  zoom: 13
});

map.addListener("zoom_changed", () => {
    if (map.getZoom() < 8) {
        console.log(map.getZoom() + " Get States")
        map.data.forEach(function(feature) {
            map.data.remove(feature);
        });
        map.data.loadGeoJson(
            "data/states.json"
        );
    }
    else {
        console.log(map.getZoom() + " Get Counties")
        map.data.forEach(function(feature) {
            map.data.remove(feature);
        });
        map.data.loadGeoJson(
            "data/counties.json"
        );
    }
});