title: How to get user code for device code flow in identity server 4
body: <p>I'm trying to use Device Code Flow which is already implemented in IdentityServer4 but in the documentation, I couldn't find anything useful about Device Code Flow. I find out an example of Device Code Flow but I don't understand what is User Code, how to get or save it.</p>
  
  <p>Here is the basic service which is used to get the context of authorization.</p>
  
  <pre><code>    private readonly IDeviceFlowInteractionService _interaction;
  
      public DeviceController(
          IDeviceFlowInteractionService interaction)
      {
          _interaction = interaction;
          _clientStore = clientStore;
          _resourceStore = resourceStore;
          _events = eventService;
          _logger = logger;
      }
  
      private async Task&lt;DeviceAuthorizationViewModel&gt; BuildViewModelAsync(string userCode, DeviceAuthorizationInputModel model = null)
      {
          var request = await _interaction.GetAuthorizationContextAsync(userCode);
          // Some code ...
          return null;
      }
  </code></pre>
  
  <p>As you can see above I've use GetAuthorizationContext which has parameter userCode but I didn't understand how to get this code ? or where to save it. In the documentation, I didn't find anything about UserCode.</p>