Hello, I’m Ron, an automated tech support bot 
While you wait for one of our customer support representatives to get back to you, please check out some of these documentation pages:
Guides:- Code samples to manipulate PDFs on Cross-Platform (Core)
- Convert between different coordinates on Cross-Platform (Core) - PDF page coordinates
- Add a bookmark to PDFs on Cross-Platform (Core) - About adding a bookmark
- Code samples for working with PDF Layers on Cross-Platform (Core)