I can't send data to database using ajax and php - php

Question

For some reason I can't get data to send to my database using ajax and php.
I click the add to cart button, the success message doesn't show up at all, and no data is sent to the database. No errors show up at all. What is going on here?
<form action="includes/addcart.inc.php?id=<?= $row['id'] ?>" class="cart-form">
<input type="hidden" class="pid" value="<?= $row['id'] ?>">
<input type="hidden" class="pname" value="<?= $row['product_name'] ?>">
<input type="hidden" class="pprice" value="<?= $row['product_price'] ?>">
<input type="hidden" class="pimage" value="<?= $row['product_image'] ?>">
<input type="hidden" class="pcode" value="<?= $row['product_code'] ?>">
<input type="submit" class="atcbutton btn btn-info btn-block" name="Add To Cart" value="Add To Cart">
</form>
Here is the form I'm using.
$(document).ready(function() {
// Send product details in the server
$('.cart-form').submit(function(e) {
e.preventDefault();
var $form = $(this).closest(".cart-form");
var pid = $form.find(".pid").val();
var pname = $form.find(".pname").val();
var pprice = $form.find(".pprice").val();
var pimage = $form.find(".pimage").val();
var pcode = $form.find(".pcode").val();
var pqty = $form.find(".pqty").val();
$.ajax({
url: 'includes/addcart.inc.php',
method: 'POST',
data: {
pid: pid,
pname: pname,
pprice: pprice,
pqty: pqty,
pimage: pimage,
pcode: pcode
},
success: function(response) {
$("#message").html(response);
}
});
});
});
Here's the js and ajax.
<?php
require 'dbh.inc.php';
if (isset($_POST['pid'])) {
$pid = $_POST['pid'];
$pname = $_POST['pname'];
$pprice = $_POST['pprice'];
$pimage = $_POST['pimage'];
$pcode = $_POST['pcode'];
$pqty = $_POST['pqty'];
$total_price = $pprice * $pqty;
$sql = ('SELECT product_code FROM cart WHERE product_code=?');
$stmt = mysqli_stmt_init($conn);
mysqli_stmt_prepare($stmt, $sql);
mysqli_stmt_bind_param($stmt, 's', $pcode);
mysqli_stmt_execute($stmt);
$res = mysqli_stmt_get_result($stmt);
$r = mysqli_fetch_assoc($res);
$code = $r['product_code'] ?? '';
if (!$code) {
$query = ('INSERT INTO cart (product_name, product_price, product_image, qty, total_price, product_code) VALUES (?,?,?,?,?,?)');
mysqli_stmt_init($conn);
mysqli_stmt_bind_param($query, 'ssssss', $pname, $pprice, $pimage, $pqty, $total_price, $pcode);
mysqli_stmt_execute($query);
echo '<div class="alert alert-success alert-dismissible mt-2">
<button type="button" class="close" data-dismiss="alert">×</button>
<strong>Item added to your cart!</strong>
</div>';
} else {
echo '<div class="alert alert-danger alert-dismissible mt-2">
<button type="button" class="close" data-dismiss="alert">×</button>
<strong>Item already added to your cart!</strong>
</div>';
}
}
header("location: ../shop");
exit();
and that's the php. (dbh.inc.php is just a simple database connection)
I have tried double checking for typos/errors and I can't seem to find anything wrong.