CODE EXAMPLE FOR JAVASCRIPT

jquery ajax

// jquery ajax
<script>
        let categoryName = $('select[name="category"]')
        let subcategory = $('select[name="subcategory"]')
        categoryName.on('change',function(){
                let myUrl = `{{ route('products.ajax', ':id') }}`
                let id = $(this).val()
                let newUrl = myUrl.replace(':id', id);
                $.ajax({
                    url: newUrl,
                    dataType: 'json',
                    type: 'get',
                    success: function (response){
                        let options =[]
                        response.map(element => {
                            let option = `<option value="${element.id}">${element.name}</option>`;
                            options.push(option)
                        })
                        subcategory.html('')
                        subcategory.html(options)
                    },
                    error: function(data){
                       let option = `<option disable>${data.responseText}</option>`
                       
                       subcategory.html('')
                        subcategory.html(option)
                    }
                })
            })
        </script>