After creating a WebAPI/MVC project within VS2019 and trying to browse using IISExpress the following error message is received:

ASP.NETCore1

The launchSettings.json file will have a default setting of windowsAuthentication =false but this setting seems to not be enforced while the app is running.

ASP.NETCore2

In order to launch the WebAPI/MVC within IISExpress for debugging purposes add a Web.config file with the following highlighted setting:

ASP.NETCore3