Create a new element in an array in c #

I would like you to help me how I could generate a new object in the Product list, it's a simple CRUD

using ProductsApp.Models;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Net.Http;
using System.Web.Http;

namespace ProductsApp.Controllers
{
    public class ProductsController : ApiController
    {
        Product[] products = new Product[]
            {
                new Product { Id = 1, Name = "Tomato Soup", Category = "Groceries", Price = 1  },
                new Product { Id = 2, Name = "Yo-yo", Category = "Toys", Price = 3.5M  },
                new Product { Id = 3, Name = "Hammer", Category = "Hardwarw", Price = 16.99M  }
            };



        public IEnumerable<Product> GetAllProducts()
        {
            return products;
        }

        public IHttpActionResult GetProduct(int id)
        {
            var product = products.FirstOrDefault((p) => p.Id == id);
            if (product == null)
            {
                return NotFound();
            }
            return Ok(product);
        }


    }
}