Edit in JSFiddle

<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <link rel="stylesheet" href="https://unpkg.com/[email protected]/dist/leaflet.css">
    <script src="https://unpkg.com/[email protected]/dist/leaflet.js"></script>
  </head>

  <body>
    <div id="map"></div>

  </body>
</html>
#map {
  height: 300px;
}
var mymap = L.map('map');

L.tileLayer('https://cyberjapandata.gsi.go.jp/xyz/std/{z}/{x}/{y}.png', {
  maxZoom: 18,
  attribution: '<a href="https://maps.gsi.go.jp/development/ichiran.html" target="_blank">国土地理院</a>',
}).addTo(mymap);

mymap.setView([37.508106, 139.930239], 13);