formData append issue with laravel validation

I am getting validation errors, I have tried below code

    var FD = new FormData();    
    FD.append( 'title', "my title" );
    FD.append( 'user_id', "20" );
    FD.append( 'company_id', "30" );

  $.ajax(
       {
       beforeSend: function (xhr) {
                xhr.setRequestHeader('Authorization', 'Bearer bde....');
                xhr.setRequestHeader('Accept', 'application/json');
                xhr.setRequestHeader('Content-Type', 'application/json');
                },
       url: 'http://localhost/myappname/public/api/test_team',
       data: FD,
       dataType: "JSON",
       processData: false,
       contentType: false,
       type: 'POST',
       success: function(data){
           alert(data);
       }
       });

Here is my controller code

$validator = validator::make($request->all(), [
        'title'     => 'required',
        'user_id' => 'required',
        'company_id'=>'required',

    ]);

    if ($validator->fails()) {
        return response()->json([
            'status'=>'false',
            'message'=>$validator->errors(),
            'code'=>400,
            'result'=>''
        ], 400);
    }

I am getting this error

"{"title":["The title field is required."],"user_id":["The user id field is required."],"company_id":["The company id field is required."]}"

Note: I want to append all my data to formData and submit it. It is working properly in POSTMAN form-data.

via Chebli Mohamed