You can't use Document Viewer to edit files.
Phil Bull
philbull@gmail.com

크리에이티브 커먼즈 동일조건변경허락 3.0

조성호
shcho@gnome.org 2012, 2013, 2018, 2021, 2022, 2023.
류창우
cwryu@debian.org 2014-2015

# Can I edit documents in Document Viewer?

Document Viewer can't be used to make changes to documents. You need to use the appropriate editing application for the type of file you want to change.

PDF files are not usually intended to be edited, but PDF editing software is available. Try LibreOffice Draw or Okular, for example. Furthermore, pdfarranger allows rearranging or removing pages and merging files.