CURL PHP 发送文件文件扩展名错误

im 尝试通过 cURL 将两个文件发送到 API。它似乎有效，除了 API 回来并说不允许文件类型。响应是：

string(189) 
{
    "StatusId": -1,
    "Success": false,
    "ReturnObject": null,
    "Message": "Please check the file format of the uploaded files. We currently only support .pdf .jpg, .png, .bmp and .gif file extensions.
}

如您所见，API JSON 响应意味着它可以看到有文件，但只是认为它们没有扩展名。我查看了文件和文件扩展名的绝对URL，它们都是JPG或PDF。有什么想法吗？

这是我的 cURL 代码：

 // send a file
curl_setopt($request, CURLOPT_POST, true);
curl_setopt(
    $request,
    CURLOPT_POSTFIELDS,
    array(
        'ClientID' => $client,
      'file' =>
          '@'.realpath(__DIR__ . '/..').'/webroot/img/uploads/documents/'.$_FILES['image']['name'],
       'file2' =>
          '@'.realpath(__DIR__ . '/..').'/webroot/img/uploads/documents/'.$_FILES['image1']['name']
    ));
curl_setopt(
    $request, CURLOPT_HTTPHEADER, array(
            "authentication: XXXXXXXXXXXXX",
            "cache-control: no-cache",
            "content-type: multipart/form-data;"));
curl_setopt(
    $request, CURLOPT_CUSTOMREQUEST, "POST");
// output the response
curl_setopt($request, CURLOPT_RETURNTRANSFER, true);
var_dump(curl_exec($request));
// close the session
curl_close($request);