title: .NET Core 3 using IUrlHelper in ControllerBase
body: <p>I have a NET Core 3.1 REST API in and have configured the start up with <code>services.AddControllers</code> since I don't need views etc; it is also using endpoint routing.</p>
  
  <p>However, I cannot generate the urls for newly created resources since the ControllerBase.Url property is null.</p>
  
  <p>The code looks a bit like this..</p>
  
  <pre><code>pubic IActionResult Post(OrderRequest request)
  {
      var order = service.CreateOrder(request);
  
      var url = Url.Link("Get", new { id = order.Id });
  
      return new CreatedResult(url, result);
  }
  </code></pre>
  
  <p>So the questions are:</p>
  
  <ul>
  <li>Should I be injecting LinkGenerator instead.</li>
  <li>How can I change startup so that ControllerBase.Url is populated</li>
  <li>Is this a bug?</li>
  </ul>