Google Maps JavaScript API 我想在源标记 A 和目标标记 B 上方显示标签

Question

我是 Google Maps API 的初学者，我现在可以使用 google.maps.Marker 但它正在创建一个新标记，而不是将标签放在源和目的地上方

function initMap() {
                const directionsRenderer = new google.maps.DirectionsRenderer();
                const directionsService = new google.maps.DirectionsService();
                const map = new google.maps.Map(document.getElementById("map"), {
                zoom: 14,
                   
                    center: { lat: 17.3848921, lng: 78.4867274 },
                });
    
                directionsRenderer.setMap(map);
                calculateAndDisplayRoute(directionsService, directionsRenderer);
                document.getElementById("mode").addEventListener("change", () => {
                    calculateAndDisplayRoute(directionsService, directionsRenderer);
                });


function calculateAndDisplayRoute(directionsService, directionsRenderer) {
            const selectedMode = document.getElementById("mode").value;

            directionsService
                .route({

                    origin: { lat: 17.3849973, lng: 78.4866993 },
                    destination: { lat: 15.3173, lng: 75.7139 },

                    // Note that Javascript allows us to access the constant
                    // using square brackets and a string value as its
                    // "property."
                    travelMode: google.maps.TravelMode[selectedMode],

                })