code>Window -&gt; Package manager</code>), selecting the <code>Advanced</code> drop down and clicking on <code>Advanced Project Settings</code>, then Adding the following details:
<blockquote>
<p>Name: XRTK</p>
<p>URL: <a href="http://upm.xrtk.io:4873">http://upm.xrtk.io:4873</a></p>
<p>Scope(s): com.xrtk</p>
</blockquote>
</li>
<li>Return to the Unity Package manager and select <code>My Registries</code> in the Sources) dropdown (next to the <code>+</code> symbol)</li>
<li>Select the <code>XRTK.SDK</code> 