title: Cant get code highlights in AspDotNet Core 3.1 Swashbuckle SwaggerUI
body: <p>I'm having <code>Swashbuckle.AspNetCore 6.1.2</code> package with following setup in <code>Startup.cs</code> file:</p>
  <pre><code>private readonly IWebHostEnvironment env;
  
  public void Configure(IApplicationBuilder app)
  {
      app.UseSwagger(c =&gt; { c.RouteTemplate = &quot;docs/{documentName}/swagger.json&quot;; });
  
      app.UseSwaggerUI(c =&gt;
      {
          c.SwaggerEndpoint(&quot;/docs/v1/swagger.json&quot;, &quot;API&quot;);
          c.ConfigObject.AdditionalItems.Add(&quot;syntaxHighlight&quot;, true);
      });
  }
  
  
  public void ConfigureServices(IServiceCollection services)
  {
      services.AddSwaggerGen(c =&gt;
      {
          c.SwaggerDoc(&quot;v1&quot;,
              new OpenApiInfo {Title = &quot;My API&quot;, Version = &quot;v1&quot;});
      });
  }
  </code></pre>
  <p>and my swagger UI looks like this:
  <a href="https://i.stack.imgur.com/8OR31.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/8OR31.png" alt="enter image description here" /></a></p>
  <p>but I expect the code to be highligted as on this picture:
  <a href="https://i.stack.imgur.com/aTqNw.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/aTqNw.png" alt="enter image description here" /></a></p>
  <p>As you see i have this line (ref: <a href="https://stackoverflow.com/a/64696778/2470538">https://stackoverflow.com/a/64696778/2470538</a>)</p>
  <pre><code>    c.ConfigObject.AdditionalItems.Add(&quot;syntaxHighlight&quot;, true);
  </code></pre>
  <p>With or without it, nothing changes.</p>