Add user to local database after registration in Stormpath - asp.net-core

Question

I want to add new user to my local database after register in Stormpath. In doc https://docs.stormpath.com/dotnet/aspnetcore/latest/registration.html#registration is section about post-registration handler. I have problem becouse i can't use UserRepository in StartUp file.
I have error:
Unable to resolve service for type
'AppProject.Repositories.IUserRepository' while attempting to
activate 'AppProject.Startup'
.
public void ConfigureServices(IServiceCollection services, IUserRepository userRepository)
{
services.AddStormpath(new StormpathOptions()
{
Configuration = new StormpathConfiguration()
{
Client = new ClientConfiguration()
{
ApiKey = new ClientApiKeyConfiguration()
{
Id = "xxxxxxxxxxx",
Secret = "xxxxxxxxx"
}
}
},
PostRegistrationHandler = (context, ct) =>
{
return MyPostRegistrationHandler(context, ct, userRepository);
}
});
}
private Task MyPostRegistrationHandler(PostRegistrationContext context, CancellationToken ct, IUserRepository userRepository)
{
userRepository.Add(new User(context.Account.Email, context.Account.FullName, context.Account.GivenName, context.Account.Surname, context.Account.Username));
userRepository.SaveChangesAsync();
return Task.FromResult(0);
}

Answer 1

In this scenario, I don't think it can resolve dependency of IUserRepository in StartUp. You can try something like this.
1) Add an extension method.
public static IServiceProvider AddServices(this IServiceCollection services)
{
services.AddTransient<IUserRepository, UserRepository>();
// rest of the things.
return services.BuildServiceProvider();
}
2) Get the userRepository instance like like this.
IServiceCollection services = new ServiceCollection();
services.AddServices();
var provider = services.BuildServiceProvider();
var userRepository = provider.GetRequiredService<IUserRepository>();
ConfigurationServices will not have IUserRepository input parameter.