GroupMe API Callback
<p>So, I am trying to use GroupMe's API. The issue is that I don't really know how to get the users access_token once I send them to the site to login. I don't really know how to create a callback or how to use it. So to sum it up</p>

<p>I need to send users to this site
<code>https://oauth.groupme.com/oauth/authorize?client_id=CLIENT_ID</code>,
then they login and groupme sends them to here
<code>https://YOUR_CALLBACK_URL/?access_token=ACCESS_TOKEN</code>.</p>

<p>But I don't know how/where to create a callback url. Then I don't know how to send that access_token back to the app.</p>

<p>Thanks.</p>