using System;

using System.Collections.Generic;

using Microsoft.AspNetCore.WebUtilities;

using Microsoft.Extensions.Primitives;

public class Program

{

    public static void Main()

    {

        var endpoint = "v1/api/endpoint";

        var arrayOfIds = new[] { "1", "2", "3" };

        var queryString = new []

        {

            new KeyValuePair<string, string>("id", new StringValues(arrayOfIds)),

            new KeyValuePair<string, string>("other", "value")

        };

        Console.WriteLine(QueryHelpers.AddQueryString(endpoint, queryString));

    }

}