CI4 PDF Customized

I installed it as an unzip into thirdparty/TCPDFMaster and created a file MyPdf.php in libraries with the following

PHP Code:

<?php namespace App\Libraries;
use App\ThirdParty\TCPDFmaster\Tcpdf;
class MyPdf extends TCPDF {
    function __construct()
    {
        parent::__construct();
    }
} 


and then in my controller

PHP Code:

$pdf = new MyPdf();
        $pdf->AddPage();
        $pdf->writeHTMLCell(....
        etc etc
        $filename=whatever;
        $file = fullpathto $filename;
        // save as file
        $pdf->Output($file, 'F');
        // send to browser
        $this->response->setHeader('Content-Type', 'application/pdf');
        $this->response->setHeader('Content-Disposition: inline;', 'filename="' . $filename . '"');
        $this->response->setHeader('Content-Transfer-Encoding', 'binary');
        $this->response->setHeader('Content-Length: '. filesize($file),'');
        $this->response->setHeader('Accept-Ranges:', 'bytes');
        readfile($file);