dependent dropdown in laravel

1 <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.5.1/jquery.min.js"></script>
2
3    <script type="text/javascript">
4        $(document).ready(function () {
5            $(document).on('change','.productCategory',function () {
6                // console.log('hmm its change')
7                var sub_cat=$('select[name="sub_cat_id"]')
8                var category_id=$(this).val();
9                // console.log(category_id);
10                var div=$(this).parent();
11
12                // var op=" ";
13
14                $.ajax({
15                   type:'get',
16                   url:'{!!URL::to('findsubcategory')!!}',
17                    data:{'id':category_id},
18                    success:function (data) {
19                        // console.log('success');
20                        //
21                        // console.log(data);
22                        // console.log(data.length);
23
24                        var op= `<option disabled="true" selected="true">---Select Sub category---</option>`;
25
26                        for (var i=0;i<data.length;i++) {
27                            op += '<option value="' + data[i].id + '">' + data[i].sub_cat_name + '</option>';
28
29                        }
30
31                        sub_cat.html(op);
32
33                    },
34                    error:function () {
35
36                    }
37                });
38            });
39        });
40    </script>