Maatwebsite not exporting in Laravel php

I have a problem in which I cannot trace the error/problem when trying to export and download my Users table in excel using Maatwebsite I’ve followed step by step with this reference here link but it didn’t export the data through excel,

Is there any wrong with my implementation? Is somebody have an idea what’s the problem? I appreciate any comments

index.blade.ph

<li class="navi-item">
     <a href="#" class="navi-link">
           <span class="navi-icon">
               <i class="la la-file-excel-o"></i>
           </span>
           <span class="navi-text" @click="exportData()">Excel</span>
     </a>
</li>

Index.js

methods: {
    init() {
       var vm = this;
       var t;
       $(document).ready(function() {
          vm.$toaster.init();
          vm.setConfig();
          });
        },
    exportData(){
       let vm = this;
       $.ajax({
           url: vm.$route('staff.ajax.emvvalidationdetails.exportemv'),
           type: 'GET',
           success: function (response) {
             if (response) {        
                        // console.log("Test");                  

                    }
                },

            });

        },

Staff ajax

 Route::group(['prefix' => 'emvvalidationdetails', 'namespace' => 'Emvvalidationdetails'], function () {
    Route::get('exportemv', 'EmvvalidationdetailsController@exportemv')->name('staff.ajax.emvvalidationdetails.exportemv');
});

EmvvalidationdetailsController

  use IlluminateSupportFacadesInput;
  use MaatwebsiteExcelFacadesExcel;
  use AppImportsImportUser;
  use AppExportsExportUser;
  use AppModelsUser;

  public function exportemv(Request $request){
    return Excel::download(new ExportUser, 'users.xlsx');
}

ExportUser.php in app/Exports

<?php

  namespace AppExports;
  use AppModelsUser;
  use MaatwebsiteExcelConcernsFromCollection;

  class ExportUser implements FromCollection
  {
   /**
   * @return IlluminateSupportCollection
   */
   public function collection()
  {
    return User::select('username','email','password')->get();
  }
 }