I'm trying to implement the solution proposed by [this](https://stackoverflow.com/questions/31831295/prevent-multiple-logins) user for prevent multiple logins in my application.

Actually I declared in my `Startup` class, specifically in the `Configure` method this code:

```
app.UseCookieAuthentication(new CookieAuthenticationOptions
{

});

```

the problem is that when I type: `AuthenticationType` I get nothing displayed, because `CookieAuthenticationOptions` doesn't have this property, and this is weird because also in the [documentation](https://learn.microsoft.com/en-us/dotnet/api/microsoft.aspnetcore.authentication.cookies.cookieauthenticationoptions?view=aspnetcore-2.1) the property doesn't exists anymore.

If I hover the mouse on `CookieAuthenticationOptions` I can see this namespace: `Assembly Microsoft.AspNetCore.Authentication.Cookies`.

**PS: I'm using ASP.NET CORE**