I can’t draw a Polygon on Google Maps

Question

I’m trying to square it with the coordinates, but it won’t show. There is no error in the browser, the map is created normally, only the square does not appear:

var map;

function initialize() {
    var latlng = new google.maps.LatLng(-21.723254, -49.356317);

    var options = {
        zoom:30,
        center: latlng,
        mapTypeId: google.maps.MapTypeId.SATELLITE
    };

    map = new google.maps.Map(document.getElementById('map'), options);
    var geocoder = new google.maps.Geocoder();

    var princiCoords = [
        new google.maps.LatLng(-21.724394, -49.356391),
        new google.maps.LatLng(-21.724172, -49.356479),
        new google.maps.LatLng(-21.724044, -49.356040),
        new google.maps.LatLng(-21.724257, -49.355960)
    ];

    var princiPolygon = new google.maps.Polygon({
        // Coordenadas do seu objeto
        paths: princiCoords,
        // Cor do da linha
        strokeColor: '#E12D93',
        // Opacidade da linha
        strokeOpacity: 0.8,
        // Espessura da linha
        strokeWeight: 4,
        // Cor de preenchimento do objeto
        fillColor: '#942E7C',
        // Opacidade do preenchimento
        fillOpacity: 0.35
    });

    princiPolygon.setMap(map);
}

initialize();