Asp.Net MVC controller and webix form

Webix JS
#1

Hello! I have an Asp.Net Core MVC application with authorization controller. I transferred the razor page code to the webixJS code, but it doesn’t work properly. The data is being transmitted, but there are a few points that I would like to clarify.

  1. When authorization is successful, RedirectToAction(returnUrl) occurs. How do I get a returnUrl in a POST request? And manually redirect “window.location.href = <…>”.
  2. Will there be a redirect when returning View(model) in post-version? The page is not being updated right now.
  3. The action method is marked with the [ValidateAntiForgeryToken] attribute. Error 400 occurs with it. It is not possible to change the controller code at this stage. How can this be fixed?
public class AccountController : Controller
{
    public IActionResult Login(string returnUrl)
    {
        ViewBag.returnUrl = returnUrl;
        return View();
    }

    [HttpPost]
    [ValidateAntiForgeryToken]
    public async Task<IActionResult> Login(LoginModel model, string returnUrl)
    {
        if (ModelState.IsValid)
        {
            if (/*login and password is correct*/)
            {
                return RedirectToAction(returnUrl ?? "/");
            }            
            ModelState.AddModelError(nameof(LoginModel.Login), "Invalid login or password!");
        }
        return View(model);
    }
}

WebixJS:

async function sendForm() {
    let form = $$("auth_form");
    if (form.validate()) {
        webix.ajax().post("/Account/Login", form.getValues());
  }
}