Amazon S3 Use in WordPress with Ajax to generate secure download url

add_action('wp_ajax_data_fetch_alco' , 'data_fetch_alco');
add_action('wp_ajax_nopriv_data_fetch_alco','data_fetch_alco');
function data_fetch_alco(){
 $object = $_POST["objectid"];
 require get_stylesheet_directory() .'/aws/aws-autoloader.php';
  define('AWS_KEY', 'XXXXXX');
  define('AWS_SECRET_KEY', 'XXXXXXXXXXXX');
  //define('HOST', 'http://103.2134.97.118/');
  //define('REGION', 'ap-south-1');
  $credentials = new Aws\Credentials\Credentials(AWS_KEY, AWS_SECRET_KEY);
  $s3 = new Aws\S3\S3Client([
      'version'     => 'latest',
      'region'      => REGION,
      'credentials' => $credentials
  ]);
  $result = $s3->listBuckets();
  //$object = 'AutoPlotter/AutoPlotter.zip';
  $secret_plans_cmd = $s3->getCommand('GetObject', ['Bucket' => 'infycons-software', 'Key' => $object]);
  $request = $s3->createPresignedRequest($secret_plans_cmd, '+2 minute');
  echo $request->getUri();
  die();
}

add_action( 'wp_footer', 'ajax_fetch_posts' );
function ajax_fetch_posts() {
?>
<script>
jQuery('.tab_download-evaluation .bt_bb_image').on('click', function() {
    jQuery('.download_evl .bt_bb_link').addClass('disabled');
    objectid = jQuery(this).attr('id');
    jQuery.ajax({
        url: '<?php echo admin_url('admin-ajax.php'); ?>',
        type: 'post',
        data: { 
         action: 'data_fetch_alco', 
         objectid: objectid,
        },
        success: function(data) {
          jQuery('.download_evl .bt_bb_link').attr('href', data);
          jQuery('.download_evl .bt_bb_link').removeClass('disabled');
        },
        error: function() {
            console.log("Error");
   }
    });
});
</script>
<?php
}