Next, we will add UI so that users can enter their username and password to authenticate on Centralized Authentication Servers. IdentityServer4 provides complete support to use OpenID Connect protocol and it also provides a sample UI that contains MVC controllers, views, and boilerplate code to quick-start implement the authentication scenario.

In this section, we will use the quick-start UI repository and this can be further customized based on your requirement. The files can be downloaded from https://github.com/IdentityServer/IdentityServer4.Quickstart.UI or you can also run the PowerShell command. You can run the following command from the CAS application path:

iex ((New-Object System.Net.WebClient).DownloadString('https://raw.githubusercontent.com/IdentityServer/IdentityServer4.Quickstart.UI/release/get.ps1'))

Once the files are downloaded, add the MVC and StaticFiles middleware in the Startup class as follows:

    app.UseStaticFiles(); 
    app.UseMvcWithDefaultRoute();

Now, run the authorization server and access http://localhost:5000.

The following page will be displayed: