Save an IMAP attachment to the file system

Good evening,

I am trying to do the following in a method: From an IMAP mailbox I read all mails and create an entry in a database (are tasks) from their content. This works wonderfully. Now I would like to save the attachments in the mail on the file system and note them in the DB, for this I currently do the following:

$mbox = imap_open("{" . env("IMAP_HOST") . ":" . env("IMAP_PORT") . "/imap/ssl}", env("IMAP_USER"), env("IMAP_PASS"));
$MC = imap_check($mbox);
$result = imap_fetch_overview($mbox, "1:{$MC->Nmsgs}", 0);
foreach ($result as $overview) {
    $structure = imap_fetchstructure($mbox, $overview->msgno);
    $header = imap_header($mbox, $overview->msgno);
    $date = date('Y-m-d', $header->udate);
.......
    $attachments = array();
    foreach ($structure->parts as $i => $s) {
        if (isset($s->disposition)) {
            if ($s->disposition == "attachment" && $s->subtype != 'PGP-SIGNATURE') {
                foreach ($s->dparameters as $files) {
                    if ($files->attribute == 'filename') {
                        $attachment = array('filename' => $files->value);
                        $attachment['type'] = strtoupper($s->subtype);
                        $attachment['content'] = imap_fetchbody($mbox, $overview->msgno, $i + 1);
                        $attachments[] = $attachment;
                    }
                }
            }
        }
    }

This loop reads out all attachments accordingly and writes them into an array. With the following part I want to save the file on the server and leave an entry in the database accordingly.

        $runner = 0;
        foreach ($attachments as $a) {
            if ($runner < 4) {
                $runner++;

                $fileModel = new File;

                $fileName = time() . '_' . uniqid() . '_' . $a['filename'];
               
               
               !!! $filePath = $request->file('file')->storeAs('assets', $fileName, 'local');!!!

                $fileModel->name = time() . '_' . uniqid() . '_' . $a['filename'];
                $fileModel->file_path = '/storage/' . $filePath;
                $fileModel->customname = $a['filename'];
                $fileModel->save();
                $fileId = $fileModel->id();

                $salestask = Salestask::find($taskid);
                $salestask->files()->attach($fileId);
            }
        }
        imap_delete($mbox, $overview->msgno);

    }

    imap_expunge($mbox);

}

It's about the part with the exclamation marks in native PHP I would do that:

file_put_contents('/path/to/folder/' . $a['filename'], base64_decode($a['content']));

However, what is the best way to implement this in Laravel?