C# Online Compiler | .NET Fiddle

using System;
using System.Linq;
using System.Collections.Generic;
using System.Security.Claims;
					
public class Program
{
	public static void Main()
	{
            var claims = new List<Claim>
            {
                new Claim(ClaimTypes.Name,"test name"),
                new Claim("Token","token123"),
                new Claim("Number","3")
                //new Claim("dummy","dummy string")
            };
            var ci = new ClaimsIdentity(claims);

            //most seen way, throw error if not exists
            var name = ci.Claims.First(x => x.Type == ClaimTypes.Name).Value;
            var token = ci.Claims.First(x => x.Type == "Token").Value;
		    //using FirstOrDefault() only, throw error if not exists
            //var dunno = ci.Claims.FirstOrDefault(x => x.Type == "dunno").Value;

            //safe way: using HasClaim to check
            var dummy = ci.HasClaim(x => x.Type == "dummy")
                ? ci.Claims.First(x => x.Type == "dummy").Value
                : null;
		    
            //short way: using FindFirst
            var dummyShort = ci.FindFirst("dummy")?.Value;
            //short way for int
            int.TryParse(ci.FindFirst("Number")?.Value, out var number);

            //fixed FirstOrDefault way: return null if not exists
            var dunno = ci.Claims.Where(x => x.Type == "dunno").Select(x => x.Value).FirstOrDefault();

            
            Console.WriteLine($"Name:{name}");
            Console.WriteLine($"Token:{token}");
            Console.WriteLine($"dunno:{dunno??"null"}");
            Console.WriteLine($"dummy:{dummy??"null"}");
			Console.WriteLine($"dummy:{dummyShort ?? "null"}");
            Console.WriteLine($"Number:{number}");
	}
}

 
using System;
using System.Linq;
using System.Collections.Generic;
using System.Security.Claims;
                    
public class Program
{
    public static void Main()
    {
            var claims = new List<Claim>
            {
                new Claim(ClaimTypes.Name,"test name"),
                new Claim("Token","token123"),
                new Claim("Number","3")
                //new Claim("dummy","dummy string")
            };
            var ci = new ClaimsIdentity(claims);
​
            //most seen way, throw error if not exists
            var name = ci.Claims.First(x => x.Type == ClaimTypes.Name).Value;
            var token = ci.Claims.First(x => x.Type == "Token").Value;
            //using FirstOrDefault() only, throw error if not exists
            //var dunno = ci.Claims.FirstOrDefault(x => x.Type == "dunno").Value;
​