Laravel Ajax Add To Cart Not working 500 internal error - ajax

Question

I have code I am working on. I will list the page, the route, and the controller code. When I inspect and click on the add to cart button I get 500 internal server error and I cannot figure out what I did. It should be giving a message checking to see if the item is already in the cart and if not send a message saying item is in the cart but I can't get past the 500 internal server error.
Page
#extends('layouts.frontend.frontend')
#section('title')
Distinctly Mine - {{$products->name}}
#endsection
#section('content')
<div class="py-3 mb-4 shadow-sm babyblue border-top">
<div class="container">
<h6 class="mb-0">Collections / {{$products->category->name}} / {{$products->name}}</h6>
</div>
</div>
<div class="container">
<div class="card-shadow shadow-sm product_data">
<div class="card-body">
<div class="row">
<div class="col-md-4 border-right">
<div class="img-hover-zoom img-hover-zoom--xyz card-img-top">
<img src="{{ asset('backend/uploads/products/'.$products->image) }}" class="w-100 h-100" alt="{{$products->name}}">
</div>
</div>
<div class="col-md-8">
<h2 class="mb-0">{{ $products->name}}</h2>
<hr>
<label for="" class="me-3">Price: ${{$products->original_price}}</label>
<p class="mt-3">{!! $products->small_description !!}</p>
<hr>
#if($products->qty > 0)
<label for="" class="badge bg-success text-dark fw-bold">In Stock</label>
#else
<label for="" class="badge bg-danger text dark fw-bold">Out of Stock</label>
#endif
<div class="row mt-2">
<div class="col-md-2">
<input type="hidden" value="{{$products->id}}" class="prod_id">
<label for="Quantity">Quantity</label>
<div class="input-group text-center mb-3" style="width:130px">
<button type="button" class="input-group-text decrement-btn">-</button>
<input type="text" name="quantity" value="1" class="form-control qty-input" />
<button type="button" class="input-group-text increment-btn">+</button>
</div>
</div>
<div class="col-md-10">
<br />
<button type="button" class="btn btn-warning text-dark fw-bold ms-3 float-start"><i class=" me-1 fa fa-heart text-danger me-1"></i>Add To Wishlist</button>
<button type="button" class="btn btn-success ms-3 float-start text-dark fw-bold addToCartBtn"><i class="me-1 fa fa-shopping-cart text-dark me-1"></i>Add to Cart</button>
</div>
<hr>
<h2>Description</h2>
{{$products->description}}
</div>
</div>
</div>
</div>
</div>
</div>
#endsection
#section('scripts')
<script>
$(document).ready(function (){
$('.addToCartBtn').click(function (e){
e.preventDefault();
var product_id = $(this).closest('.product_data').find('.prod_id').val();
var product_qty = $(this).closest('.product_data').find('.qty-input').val();
$.ajaxSetup({
headers: {
'X-CSRF-TOKEN': $('meta[name="csrf-token"]').attr('content')
}
});
$.ajax({
method: "POST",
url: "/add-to-cart",
data: {
'product_id': product_id,
'product_qty': product_qty,
},
dataType: "dataType",
success: function (response){
alert(response.status);
}
});
});
$('.increment-btn').click(function (e){
e.preventDefault();
var inc_value = $('.qty-input').val();
var value = parseInt(inc_value,10);
value = isNaN(value) ? 0 :value;
if(value < 10)
{
value++;
$('.qty-input').val(value);
}
});
$('.decrement-btn').click(function (e){
e.preventDefault();
var dec_value = $('.qty-input').val();
var value = parseInt(dec_value,10);
value = isNaN(value) ? 0 :value;
if(value > 1)
{
value--;
$('.qty-input').val(value);
}
});
});
</script>
#endsection
Route
Route::middleware(['auth'])->group(function (){
Route::post('/add-to-cart',[CartController::class,'addProduct']);
});
Controller
<?php
namespace App\Http\Controllers\Frontend;
use App\Models\Product;
use Illuminate\Http\Request;
use App\Http\Controllers\Controller;
use Illuminate\Support\Facades\Auth;
class CartController extends Controller
{
public function addProduct(Request $request)
{
$product_id = $request->input('product_id');
$product_qty = $request->input('product_qty');
if(Auth::check())
{
$prod_check = Product::where('id',$product_id)->first();
if($prod_check)
{
if(Cart::where('prod_id',$product_id)->where('user_id',Auth::id())->exists())
{
return response()->json(['status' => $prod_check->name." Already Added to cart"]);
}else{
$cartItem = new Cart();
$cartItem->prod_id = $product_id;
$cartItem->user_id = Auth::id();
$cartItem->prod_qty = $product_qty;
$cartItem->save();
return response()->json(['status'=>$prod_check->name." Added to cart"]);
}
}
}
else{
return response()->json(['status'=> "Login To Continue"]);
}
}
}