Use Bike layer openstreetMap javascript

I would like to use the bike layer like this one:

https://www.openstreetmap.org/#map=14/37.7874/-2.9519&layers=C

But I don´t know which url to use. At the moment I have just the default one:

var map = L.map('map');
L.tileLayer('http://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png', {
  attribution: 'Map data &copy; <a href="http://www.osm.org">OpenStreetMap</a>'
}).addTo(map);

Any ideas?

Code from: https://github.com/mpetazzoni/leaflet-gpx