I am trying to convert the ppt file to odp in PHP but it gives me error
$api = new SlidesApi(null, $config);
$request = new PostSlidesConvertRequest(ExportFormat::ODP,
fopen('/opt/lampp/htdocs/rr/web/img_assets/documents/newold.pptx', 'r'));
$result = $api->postSlidesConvert($request);
echo "My PDF was saved to " . $result->getPathname();
here this error message preg_match() expects parameter 2 to be string, resource given