why does an apostrophe in a filename loaded on a reference page redirect the page to a 404 page [closed]

i made a project reference page. i use html with php and send data with post method. Users fill in fields and upload a file. When they press the submit button, although the php page exists, the file name contains an apostrophe ('), so I see a 404 page. Does anyone know why this error occurs?

I do not use the file name when uploading it to the system. If the post comes to these codes, there will be no problem. As soon as I press the send button, the 404 page appears. But there are codes on the page.

$boyut = $_FILES['b1b']['size'];
  if($boyut > (1024*1024*1024)){
     echo 'Dosya 10MB den büyük olamaz.';
  } else {
     $tip = $_FILES['b1b']['type'];
     $isim = $_FILES['b1b']['name'];
     $uzanti = explode('.', $isim);
    $_name_ = substr(md5(rand(0,9999999999)),-10)."mef.".$uzanti[1];
    $uzanti = strtolower($uzanti[count($uzanti)-1]);
    
        $dosya = $_FILES['b1b']['tmp_name'];
        copy($dosya, 'upload/' . $_name_);
        $b1b=$_name_; }