In ASP.NET, you configure email for Identity in IdentityConfig.cs in the App\_Start folder, as per my own answer [here](https://stackoverflow.com/a/36803600/5750078).

ASP.NET Core Identity [is now a library](https://devblogs.microsoft.com/aspnet/aspnetcore-2-1-identity-ui/). And does not include this IdentityConfig.cs file by default. So how can I configure email sending, say, for Registration confirmation?