Error module pdfexport:Uncaught Error ReportController.php:119

hello, recently I installed the pdf export module (guiding me through this page: https: //prakash-khadka.com.np/icinga2-installing-reporting-module-for-sla/) of icinga web2 in debian 10 to generate pdf reports of the monitored computers, but when I want to generate a report I get the following error:

I hope you can help me

Try the master of the pdfexport module, this will work.