How to handle the data received to save it in the database Laravel and Ajax?

I'm trying to add the product with multiple images to the database without refreshing the page, I don't get any errors on console but I see the long text which starting like this <script> Sfdump = window.Sfdump || (function (doc) { var refStyle = doc.createElement('style'), rxEsc = /([.*+?^${}()|\[\]\/\\])/g, idRx = /\bsf-dump-\d+-ref[012]\w+\b/, keyHint = 0 <= navigator.platform.toUpperCase().indexOf('MAC') ? 'Cmd' : 'Ctrl', addEventListener = .... and the error comes from this line console.log(data);. The product has a relationship with ProductsPhoto,how can I make it add the product to the database?

Controller

 public function store(Request $request)
 {
    $formInput=$request->except('filename');

    $product = product::create(array_merge($formInput, [
        'seller_id'=> Auth::user()->id,
        'user_id' => Auth::user()->id
    ]));
    foreach ($request->photos as $photo) {
       $filename = $photo->store('public/photos');
        ProductsPhoto::create([
            'product_id' => $product->id,
            'filename' => $filename
        ]);
    }
}

Blade

  <div class="panel-body">

   <input type="hidden" value="" id="token"/>

     <label for="pro_name">Name</label>
      <input type="text" class="form-control" name="pro_name" id="pro_name" placeholder="Enter product name">

        <label for="pro_price">Price</label>
           <input type="text" class="form-control" name="pro_price" id="pro_price" placeholder="Enter price">

        <label for="pro_info">Description</label>
         <input type="text" class="form-control" name="pro_info" id="pro_info" placeholder="Enter product description">

           <label for="stock">Stock</label>
            <input type="text" class="form-control" name="stock" id="stock" placeholder="Enter stock">

        <label  for="category_id">Choose Category</label>
           <select name="category_name" id="category_name">
             <option value=""> --Select Category -- </option>
               @foreach ($categoryname_array as $data)
                <option value=""  ></option>
                 @endforeach
               </select>

 <label for="photos">Choose 5 Images</label>
  <input  "multiple="multiple" id="photos" name="photos[]" type="file">

  <input type="submit" class="btn btn-primary" value="Submit" id="btn"/>

</div>

Ajax

   $(document).ready(function(){
   $("#btn").click(function(){
    var category_name = $("#category_name").val()
    var pro_name = $("#pro_name").val();
    var pro_price = $("#pro_price").val();
    var stock = $("#stock").val();
    var pro_info = $("#pro_info").val();
    var photos = $("#photos").val();
    var token = $("#token").val();

    $.ajax({

        type: "post",
        data: "pro_name=" + pro_name + "&pro_price=" + pro_price + "&stock=" + stock + "&_token=" + token + "&category_name=" + category_name + "&pro_info=" + pro_info + "&photos=" + photos,
        url: "<?php echo url('seller/product') ?>",
        success:function(data){
        console.log(data);
        }

    });
  });
});

Route

 Route::post('seller/product', 'ProductController@store')->name('product.store');

via Chebli Mohamed