I have an ajax call that saves some data to a database, but now I need to also download a zip file with a bunch of PDFs inside of it. My problem is that i can’t make it so the file I download isn’t corrupted. Can anyone spot if I am doing something wrong here? PHP version is 7.2.11 if that’s of any help.

Ajax code:

$.ajax({
        url: "",
        type:'POST',
        data:{data: data},
        xhrFields: {
        responseType: 'blob'
    },
        success:function(result, status, xhr){
            
          var blob = new Blob([result], { type: 'application/zip' });
          var link = document.createElement('a');
          link.href = window.URL.createObjectURL(blob);
          link.download = 'cartas_convocacao.zip';
          document.body.appendChild(link);
          link.click();
          document.body.removeChild(link);
        
            
        },

        });

Here is the PHP part of the code:

$zip = new ZipArchive();
        $zipFile = 'cartas_convocacao.zip';
        if ($zip->open($zipFile, ZipArchive::CREATE)) {
            foreach ($chapas as $key => $value) {
                if (strlen($chapas[$key]) > 0) {
                  //CODE TO CREATE PDF. SINCE IT IS ALSO CORRUPTED WITHOUT IT I DONT THINK THE PROBLEM IS HERE
                }
            }
            $zip->close();
           
            header('Content-Type: application/zip; charset=utf-8');
            header('Content-Disposition: attachment; filename="cartas_convocacao.zip"');
            header('Content-Length: ' . filesize($zipFile));
            readfile(utf8_encode($zipFile));
            
        } 

        exit();

Maybe what i am doing is not the best way of making this work. If so, could anyone give me an idea of a better way to implement this?