title: How to handle/intercept an event raised by Identity Server 4 .NET Core
body: <p>I have read in the Identity Server 4 docs that it is possible to turn on Events like so:</p>
  
  <pre><code>services.AddIdentityServer(options =&gt;
  {
      options.Events.RaiseSuccessEvents = true;
      options.Events.RaiseFailureEvents = true;
      options.Events.RaiseErrorEvents = true;
  });
  </code></pre>
  
  <p>This is all fine, but I want to know how to listen for when an event is raised, such as the 'ApiAuthenticationSuccessEvent', for example. How do listen for this event being raised in the .NET Core web app? I'm not going to be persisting the event to some Event Store somewhere, I just need to know when such an event is raised so that I can inspect the event and do something with the information.</p>
  
  <p>Perhaps I'm going about this in the wrong way, or I'm missing something obvious!</p>