This is my ajax script that use in jQuery step library. after get data from Get method in several step correctly and get with this Ajax method correctly :

  onFinished: function (event, currentIndex) {
            event.preventDefault();  
            console.log("Finish was clicked !");
            var postData = {
                CartAddresses: {
                    Address: $('#reviewAddress').val(),
                    State: $('#reviewState').val(),
                    District: $('#reviewDistrict').val(),
                    ZipCode: $('#reviewZipCode').val()
                },
                CartDeliveryDateViewModel: {
                    DeliveryDate: $('#deliveryDate').val(),
                    DeliveryTime: $('#deliveryTime').val(),
                    Details: $('#details').val(),
                    PaymentMethod: $('#paymentMethod').val()
                },
                Tax: parseFloat($('#tax').val()),

                TotalPrice: parseFloat($('#totalPrice').text()),
                FinalPrice: parseFloat($('#finalPrice').text())
            };

            var postDataJson = JSON.stringify(postData);

            console.log('postData', postData);

            $.ajax({
                url: '/UserPanel/Checkout',
                type: 'POST',
                contentType: 'application/json',
                data: postDataJson,
                success: function (response) {
                    console.log('Checkout successful:', response);
                },
                error: function (xhr, status, error) {
                    console.error('Checkout failed:', status, error);
                    alert('Error sending data. Please try again.');
                }
            });

        }`

but in post controller it does not pass to method and all data input are null. All data get correctly and I checked n console but does not get to controller input
`
[Authorize]
[HttpPost(“/UserPanel/Checkout”)]

    public IActionResult Checkout ( CheckOutViewModel checkOutViewModel)

    {
        if (checkOutViewModel != null)
        {
           
            bool isCheckoutSuccessful = true;

            if (isCheckoutSuccessful)
            {
                return Json(new { success = true, message = "Checkout completed successfully." });
            }
            else
            {
                return Json(new { success = false, message = "There was an error completing the checkout." });
            }
        }
        else
        {
       
            return BadRequest("Invalid data received.");
        }
    }

`