How to check if user already exists on client-side in ASP.NET MVC 5?

Question

Using Visual Studio 2013.4 (Visual Studio 2013 Update 4) I have created a regular ASP.NET MVC 5 project with Individual User Accoun

Answer 1

ASP.NET Core Identity is a membership system that adds login functionality to ASP.NET Core apps. Users can create an account with the login information stored in Identity or they can use an external login provider.
**code is here**
 services.Configure(options =>
            {
                options.Password.RequiredLength = 8;
                options.User.RequireUniqueEmail = true;
            });