Leaflet multiple markers on map

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName: 'Ember Twiddle',
  lat: 59.9200,
  long: 10.7450,
  zoom: 13,
  markers: [
    { name: 'Grünerløkka', coords: [59.9239, 10.7578] },
    { name: 'Majorstua', coords: [59.9268, 10.7162] }
  ],
  actions: {
    addMarker() {
      const marker = { name: 'Bislett', coords: [59.9250, 10.7334]};
      this.set('markers', [...this.markers, marker])
    }
  }
});

styles.app.css

body {
  margin: 12px 16px;
  font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif;
  font-size: 12pt;
}

.leaflet-container {
  width: 500px;
  height: 400px;
}

.marker-icon {
  width: 20px;
  height: 20px;
  background: blue;
  transform: rotate(45deg);
}

templates.application.hbs

{{#leaflet-map lat=lat lng=long zoom=zoom}}
	{{tile-layer url="https://{s}.basemaps.cartocdn.com/light_all/{z}/{x}/{y}.png"}}
  
  {{#each markers as |marker|}}
  	{{#marker-layer 
    	location=marker.coords 
      icon=(div-icon className="marker-icon")
    }}
	    {{#popup-layer}}
  		  {{marker.name}}
	    {{/popup-layer}}
    {{/marker-layer}}
  {{/each}}
{{/leaflet-map}}

<button type="button" {{action "addMarker"}}>Add marker</button>

twiddle.json

{
  "version": "0.15.1",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.js",
    "ember": "3.4.3",
    "ember-template-compiler": "3.4.3",
    "ember-testing": "3.4.3"
  },
  "addons": {
    "ember-data": "3.4.2",
    "ember-leaflet": "3.0.18"
  }
}