macOS Monterey 12.6 — What software or apps allow in-line editing of a .pdf document?

The questions I found similar relate to general .pdf editors which include adding notes, comments, etc.

I am trying to find software that allows for the editing of the source text of the text visible in an original, unmodified .pdf or in other words in-line editing of the text.

So far, I have failed to find a reliable solution.