<script>
  // Changing topojson to geojson
  L.TopoJSON = L.GeoJSON.extend({
    addData: function(jsonData) {
      if (jsonData.type === "Topology") {
        for (let key in jsonData.objects) {
          if (jsonData.objects.hasOwnProperty(key)) {
            let geojson = topojson.feature(jsonData, jsonData.objects[key]);
            L.GeoJSON.prototype.addData.call(this, geojson);
          }
        }
      } else {
        L.GeoJSON.prototype.addData.call(this, jsonData);
      }
    }
  });

  const topoLayer = new L.TopoJSON();

  fetch('{{ .Get "url" | plainify }}')
    .then(response => {
      return response.json();
    })
    .then(data => {
      topoLayer.addData(data);
      topoLayer.addTo(mymap);
    });
</script>