PDF generating blank page

[nec-developers]

I have Centos 7 + Apache + PHP 7.2.34 and installed wkhtmltopdf 0.12.6 (with patched qt) with dependencies. But when I am trying to generate booklet pdf, I am getting blank pdf file. When try to generate pdf file from command line, for example wkhtmltopdf http://www.google.com google.pdf everything works fine.
Could I get some advises what I have to do?

By the way, I have done these steps:
1- In /var/www/html/tao/config/taoBooklet/wkhtmltopdf.conf.php path to wkhtmltopdf should be /usr/local/bin/wkhtmltopdf (For some reason it is not always works with symlinks or with just 'binary' => 'wkhtmltopdf')
2- You can set 777 mode to /usr/local/bin/wkhtmltopdf (Sometimes it is also helps, I don’t know why 751 does not always work)
3- after every change you should restart php and (IMPORTANT) restart worker processes and also apache (to be 100% sure)