Query email address from claims after sign in - ASP.NET Core Razor Pages

ProtectedPage.cshtml.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.RazorPages;
using System.Security.Claims;

namespace CloudSkills.Pages
{
    public class ProtectedPageModel : PageModel
    {
        public IEnumerable<Claim> Claims { get; set; }
        public string EmailClaim { get; set; }

        [Authorize]
        public void OnGet()
        {
            this.Claims = User.Claims;

            var email = User.Claims.Where(e => e.Type == "emails")
                   .Select(e => e.Value).SingleOrDefault();
            
            this.EmailClaim = email;
        }
    }
}