title: How to correctly use the introspection endpoint with identity server 4?
body: <p>I'm using Identity Server 4 and I'm trying to use the introspection endpoint, but just by the docs I'm not getting it.</p>
  
  <p>The docs just gives this example</p>
  
  <pre><code>POST /connect/introspect
  Authorization: Basic xxxyyy
  
  token=&lt;token&gt;
  </code></pre>
  
  <p>Now, why there is this basic authentication and what should be xxxyyy? I mean, there's no basic auth set in my app. I've just setup Identity Server 4 using ASP.NET Core as follows in the <code>ConfigureServices</code>:</p>
  
  <pre><code>services.AddIdentityServer()
              .AddTemporarySigningCredential()
              .AddInMemoryApiResources(ApiResourceProvider.GetAllResources())
              .AddAspNetIdentity&lt;Usuario&gt;();
  </code></pre>
  
  <p>and in <code>Configure</code></p>
  
  <pre><code>app.UseIdentity();
  app.UseIdentityServer();
  </code></pre>
  
  <p>Now I've tried just a POST to /connect/introspect with the body just <code>token=&lt;token&gt;</code>, but it returned a 404.</p>
  
  <p>I believe I really didn't get it.</p>
  
  <p>How do we use the introspection endpoint with Identity Server 4 in ASP.NET Core?</p>