Request input laravel ajax return null on update method

I try to update data in laravel with ajax with put method, when I echo request input the result is null, this is my ajax
let formData = new FormData();
formData.append('name', 'lorem ipsum'); // I want get this

$.ajax({
   url     : 'product/17',
   method  : 'put',
   data: formData,
   contentType: false,
   processData: false,
   headers: {
      'X-CSRF-TOKEN': $('meta[name="csrf-token"]').attr('content')
   },
   success : function(res){
      alert(res); // result is null
   }
});

Route : 
Route::resource('/product', 'ProductController');

Controller :
public function update(Request $request, $id){
   echo $id; // result is 17
   echo $request->input('name'); // result is null :(
}

I have been search and try other code but not work, how to solve it? thanks

I think may be it's because of method of request. There is different way of sending put request than normal get/post request. You can modify like this:
let formData = new FormData();
formData.append('name', 'lorem ipsum'); // I want get this
formData.append('_method', 'put'); // Specify method

$.ajax({
   url     : 'product/17',
   method  : 'post',
   data: formData,
   contentType: false,
   processData: false,
   headers: {
      'X-CSRF-TOKEN': $('meta[name="csrf-token"]').attr('content')
   },
   success : function(res){
      alert(res); // result is null
   }
});

Now, You can access data with the same approach.
$request->input('name');

I hope you understand.