Why I am getting 500 (Internal Server Error) in Laravel?

I have a blade view name: create.blade.php. From here I want to call an ajax request to show a data in this blade.

{!! Form::open() !!}
   <p data-toggle="modal" data-id="" data-target="#subcategory_Modal" class="CategoryIDForModal"> 
  </p>
{!! Form::close() !!}

From here I will collect id.

Let's see the ajax request:

$.ajaxSetup({
            headers: {
                'X-CSRF-TOKEN': $('[name="_token"]').val()
            }
        });
$(".CategoryIDForModal").click(function (e) {
            //console.log("I am inside Call");
            var id = $(this).data(id);
            e.preventDefault();

            $.ajax({
                type: 'POST',
                url: '/pos/create',
                data: {id: id},
                success: function (data) {
                    console.log("YES");
                }
            })
        })

Now see the Route:

Route::post('/pos/create', 'SellPosController@ajaxRequestForSubCategoryPost');

With my controller I just want to pass a variable in my create.blade.php file.

public function ajaxRequestForSubCategoryPost(Request $request)
{
        $input = $request->all();
        return view('sale_post.create', ['inputD' => $input]);
}

But getting error:

POST http://localhost:8000/pos/create 500 (Internal Server Error)

via Chebli Mohamed