The value '' is invalid. for primary key in MVC

    public class Todo
    {
        public int Id { get; set; }
 
        public string? Name { get; set; }
    }
}

        public IActionResult Insert()
        {
            return View("_Form");
        }
        [HttpPost]
        [ValidateAntiForgeryToken]
        public async Task<IActionResult> Insert([Bind("Id, Name")]Todo todo)
        {
            if (ModelState.IsValid)
            {
                _context.Add(todo);
                await _context.SaveChangesAsync();
                return RedirectToAction(nameof(Index));
            }
            return View("_Form",todo);
        }

@model Todo
<form asp-action="Insert" id="form-action" method="post" role="form">
    <div asp-validation-summary="All"></div>
    <label asp-for="Name"></label>
    <input asp-for="Id" type="hidden" />
    <input asp-for="Name" />
    <span asp-validation-for="Name"></span>
    <input type="submit" id ="form-button" value="Add Todo" />
</form>