I am fetching certain data from the geolocation API and displaying information about a particular IP address entered by the user. I'm also displaying the location using Leaflet.js but the map doesn't work properly. I am fetching the coordinates from the API and updating the center of the map with them.

The JS code looks like this:

map = L.map('map').setView([lat, long], 13);

L.tileLayer('https://api.mapbox.com/styles/v1/mapbox/streets-v11/tiles/0/0/0?access_token='+ACCESS_TOKEN, {
    attribution: 'Map data &copy; <a href="https://www.openstreetmap.org/copyright">OpenStreetMap</a> contributors, Imagery © <a href="https://www.mapbox.com/">Mapbox</a>',
    maxZoom: 18,
    id: 'mapbox/streets-v11',
    tileSize: 1024,
    zoomOffset: -1,
    accessToken: ACCESS_TOKEN
    }).addTo(map);

L.marker([lat, long]).addTo(map)
    .bindPopup("popup")
    .openPopup();

What might be wrong?