When adding watermarks into a existed PDF file, I would like to keep the content in PDF unchanged.
From version 1.9.0 of Affinity Publisher, I learned it have started to support PDF passthrough, which seems to be the key feature to realize what I need.
I have Affinity Publisher 1.9.2 (Windows) right now.
However, after I open the original PDF file, Affinity Publisher seems to use other fonts in my PC to replace the content have missing fonts.
So, my question is: how to enable PDF passthrough functionality or how to keep the content unchanged after I try to add watermarks?
Many thanks
p.s. the following pictures are the screenshots from my PC
(1) Font Manager in Affinity Publisher
(2) What I see after opening by Affinity Publisher
(3) The original layout of PDF file