>Before you run <code>ember build</code> for this tutorial ensure you have the environment variable <code>LEAFLET_MAPS_API_KEY</code> set on your operating system,
so that you can view <a href="../service/">the maps we set up previously</a>.</p>
<p>For many Unix shell environments you can simply provide the key in front of the of the build command, such as:</p>
<pre class="language-bash line-numbers"><code class="bash language-bash"><span class="token assign-left variable">LEAFLET_MAPS_API_KEY</span><span c