如何从url使用php cURL下载pdf？

Question

Hi I am trying to download the following file with PHP (I want to download it every day): http://www.borkumer-zeitung.de/wp-content/uploads/Zeitung/2019/08/BZ_020819.pdf

When I enter the url in my browser I can open the PDF just fine. But when I try to download it using cURL I get redirected to a login page.

I tried different settings for curl_setopt but nothing seems to work. The code works but instead of downloading the pdf I get redirected to: http://www.borkumer-zeitung.de/anmelden/ and the content of this page is downloaded.

This is my code: 

$url = "http://www.borkumer-zeitung.de/wp-content/uploads/Zeitung/2019/08/BZ_020819.pdf";
$saveTo = "newspaper/newspaper.pdf";


//Open file handler.
$fp = fopen($saveTo, 'w+');

//If $fp is FALSE, something went wrong.
if($fp === false){
    throw new Exception('Could not open: ' . $saveTo);
}


//Create a cURL handle.
$ch =curl_init($url);

curl_setopt($ch,CURLOPT_USERAGENT,'Mozilla/5.0 (Windows NT 6.2; WOW64; rv:17.0) Gecko/20100101 Firefox/17.0');
curl_setopt($ch, CURLOPT_REFERER, 'http://www.borkumer-zeitung.de/3d-flip-book/02-08-2019/');
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_HEADER, false);
//Pass our file handle to cURL.
curl_setopt($ch, CURLOPT_FILE, $fp);

//Timeout if the file doesn't download after 20 seconds.
curl_setopt($ch, CURLOPT_TIMEOUT, 20);

//Execute the request.
curl_exec($ch);

//If there was an error, throw an Exception
if(curl_errno($ch)){
    throw new Exception(curl_error($ch));
}

//Get the HTTP status code.
$statusCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);

//Close the cURL handler.
curl_close($ch);

//Close the file handler.
fclose($fp);

if($statusCode == 200){
    echo 'Downloaded!';
} else{
    echo "Status Code: " . $statusCode;
}

I would love to get a hint or the solution to be able to download this file on my server :)