I installed Mod Menu to config the particles. Was met with being unable to even access the config options for this mod. I'm unable to manually edit the files as well (my computer won't let me). I do apologize if this should be an issue with Mod Menu and not Illuminations.
Version: Minecraft Fabric 1.19
Texturepack: Mizunos 16 Craft

It not showing up in ModMenu is a known issue, but what exactly do you mean by "my computer won't let me edit the config file directly"?

For some reason when I try to edit it (I looked up tutorials on how to do it), I just can't. My computer just won't open the file for some reason

Editing it while Minecraft is open usually doesn't work. You also need to make sure it's opening with a text editor (such as notepad).

I tried opening it in a different text editor that I completely forgot about notpad! Thank you. It's a shame I can't do this in-game though simply because reading stuff in notepad is really hard for me

This error may be the cause:
See in latest.log:

[14:19:51] [Render thread/ERROR]: Mod illuminations provides a broken implementation of ModMenuApi
org.quiltmc.loader.impl.entrypoint.QuiltEntrypointException: Exception while loading entries for entrypoint 'modmenu' provided by 'illuminations'
...
Caused by: java.lang.ClassNotFoundException: ladysnake.illuminations.client.IlluminationsModMenuIntegration

Checking the jar file: no such file ladysnake.illuminations.client.IlluminationsModMenuIntegration, at least in mod version illuminations-1.10.8.

Although the source code repository contains this file.

I have this problem too!!! Except effective doesnt have the config too.

Any update to this? Illuminations config still doesn't show up in mod manager (I am using 1.19.2)

This issue still persists