How to disable items merging

Hello! I'd like to ask help. How do I turn off the merge radius for PaperMC? (items merging when dropped) Isearched it up on the internet and they keep saying I can change it's value on spigot.yml/paper.yml by finding "merge-radius", but I can't find it. Can someone help me? Thanks

Oh, I understand. Why can't we access it?

Last question, do you guys have any other ways to modify it other than searching up a plugin? Just a curiosity, cause I'd really like to disable that setting for the software I'm using.