How to get data sent via ajax without form in laravel?

Question

Laravel

Good evening. There are two questions:

1) How to get in laravel via $request the data that was sent via ajax without a form? If the data is sent through a form, then we can get it through $request->input(), and without it, what property should we access?

2) Why var_dump($request->ajax()); writes "bool(false)", although after sending the console outputs "XHR finished loading: GET" and the message received from Response::json?

$.ajax({
            url: $('#get_route').data('route'),
            data: attributeId,
            headers: {'X-CSRF-TOKEN': $('meta[name="csrf-token"]').attr('content')},
            type: 'GET',
            datatype: 'JSON',
            success: function (html) {
                console.log(html);

            },
            error: 'ошибка'
        })

public function filter(Request $request)
    {
        var_dump($request->ajax());
        return Response::json(['success' => 'true', 'message' => 'OK']);

    }