When using the extension it generates an empty pdf file, message in error log: PHP Deprecated: Use of $wgParser was deprecated in MediaWiki 1.32. [Called from MediaWiki::performAction in ...mediawiki/includes/MediaWiki.php at line 543] in ..mediawiki/includes/debug/MWDebug.php on line 375. Used for single page generation, format=single.
Installation: MediaWiki 1.37.1, PHP 7.4.27, MariaDB 10.6.5-MariaDB, ICU 70.1, PdfBook 2.0.5,2021-07-19.