Class 'PhpOffice\PhpSpreadsheet\Reader\Xlsx' not found

In local system it working

on live server it is not working

i copied vendor/phpoffice

paste in server vendor folder in composer.json

"require" : {
	 "phpoffice/phpspreadsheet": "^1.15",
}

in controller

namespace App\Http\Controllers\admin;

use Illuminate\Http\Request;
use App\Http\Controllers\Controller;
use Illuminate\Support\Facades\Input;
use Illuminate\Support\Facades\Validator;
use App\Traits\CommonTrait;
use Illuminate\Support\Facades\Storage;
use Illuminate\Support\Facades\Config;
use Illuminate\Support\Facades\Session;

use Maatwebsite\Excel\Facades\Excel;

use App\Imports\ExcelImport;

use PhpOffice\PhpSpreadsheet\Reader\Xlsx;
use App\Codes;


use DB;
class ImportController extends Controller

how do i resolve this error , also maatwebsite got same error. Please tell me how to do it. in local system working fine