html2pdf Call to a member function getParam() on null

Good day everybody! Had downloaded html2pdf library. Simple test works ok!

require __DIR__.'/vendor/autoload.php';
use Spipu\Html2Pdf\Html2Pdf;
$html2pdf = new Html2Pdf();
$html2pdf->writeHTML('This is my first test');
$html2pdf->output();

http://joxi.ru/ZrJR5jltQ3kL4r

but when I tried to convert real html

$html2pdf->writeHTML($html);

I got this http://joxi.ru/EA4GObPUXP0Wy2 I really need to have this code worked. Please help

source https://stackoverflow.com/questions/71443424/html2pdf-call-to-a-member-function-getparam-on-null