我有这段HTML代码：

<div id="container">
   <div id="calendar">
   </div>
 </div>
<button class="btn btn-dark mb-1" onclick="captureAndSave()">Format</button>

还有这段js代码

<script>

  function captureAndSave() 
  {
    // Select "calendar" element
    var elementToCapture = document.querySelector('section.content');

    // Hide ".noPrint" elements
    var elementsToHide = elementToCapture.querySelectorAll('.noPrint');
    elementsToHide.forEach(function(element)
    {
      element.style.visibility = 'hidden';
    });

    html2canvas(elementToCapture).then(function(canvas) 
    {
      var imageBase64 = canvas.toDataURL('image/png');

      elementsToHide.forEach(function(element) 
      {
        element.style.visibility = 'visible';
      });

      var link = document.createElement('a');
      link.href = imageBase64;
      link.download = 'captura.png';

      link.click();
    });
  }

</script>

按下按钮应该下载内容"section.content"的图像，对吗？实际上，这个操作是成功执行的，但是当我尝试修改这段代码，使其将图像下载到服务器文件夹而不是下载到用户的计算机时，我无法做到。

我尝试了这种方法：

<script>

function captureAndSave() 
{
  var elementToCapture = document.querySelector('section.content');

  var elementsToHide = elementToCapture.querySelectorAll('.noPrint');
  elementsToHide.forEach(function (element) {
    element.style.visibility = 'hidden';
  });

  html2canvas(elementToCapture).then(function (canvas) {
    var imageBase64 = canvas.toDataURL('image/png');

    elementsToHide.forEach(function (element) {
      element.style.visibility = 'visible';
    });

    var xhr = new XMLHttpRequest();
    xhr.open('POST', 'assets/imagen.php', true);
    xhr.setRequestHeader('Content-type', 'application/x-www-form-urlencoded');

    var data = 'image=' + encodeURIComponent(imageBase64);
    xhr.send(data);

    xhr.onload = function () {
      if (xhr.status === 200) {
        var response = JSON.parse(xhr.responseText);
        if (response.success) {
          alert(response.message);
        } else {
          alert('Error: ' + response.message);
        }
      }
    };
  });
}

</script>

我尝试管理保存到服务器的名为"image.php"的PHP代码，但没有成功：

<?php
$response = array();

if(isset($_POST['image'])) 
{
  $imageData = $_POST['image'];

  $filePath = '../vistas/img/temp/imagen.png';

  if(file_put_contents($filePath, base64_decode(preg_replace('#^data:image/w+;base64,#i', '', $imageData)))) 
  {
    $response['success'] = true;
    $response['message'] = 'The image has been saved successfully.';
  } 
  else 
  {
    $response['success'] = false;
    $response['message'] = 'There was an error saving the image.';
  }
} 
else 
{
  $response['success'] = false;
  $response['message'] = 'No image received.';
}

  header('Content-type: application/json');
  echo json_encode($response);
?>

有关我可以改变的建议或者更好的方法来实现我想要的目标吗？首先，谢谢。