why my updateOrInsert doesn't work laravel

I use updateOrInsert to avoid duplicate data, why doesn't the Update function work and always insert data?

foreach($datas as $data){
                    DB::table('users')->updateOrInsert([
                        'user_connect_id' => $user->connect_id,
                        'description' => $data['description'],
                        'created_by' => $login->name,
                        'modified_by' => $login->name,
                        'created_at' => Carbon::now(),
                    ]);
                }

via Chebli Mohamed