OtherArgs definition in HTMLtoPDF

OtherArgs definition in HTMLtoPDF

  
can anybody explain how do I use the Other args parameter in HTMLtoPDF?

I want to add header images for every page, and it seems the OtherArgs parameter is the only way that I can do that.
The documentation for the rendering engine has the full instructions for the arguments:
wkhtmltopdf.org

J.Ja