Go read the correponding README of the converter you want to use, some adds very usefull stuff (but some don't)

Every converter need specifics libraries to be run, execute the corresponding libraries.bat file of the converter you want to use to automatically download everything (you need pip)
If there isn't one, it because all libraries used are built-in python libraries


Quick description of each converter :

-  png2pdf convert mutiple png into a single pdf

-  yt2mp3 convert multiple yt playlists into mutiple mp3 files

-  mp42mp3 convert mutiple mp4 file into multiple mp3 files (each mp4 file create mutiple mp3 file on its own, one for each audio track)

-  pdf(s)2pdf merge multiple pdf file into a single pdf file


After cloning the git, execute this command in the main diretory of the git before using any converter: 

- Windows : del /s /q .gitkeep

- MacOS : find yourself

Or delete manually every .gitkeep file in the git