Im not sure if im just being stupid or what but there is no config option after installing the mod with forge.

Yes as @DarianLStephens said, forge didn't re implement the config gui like in 1.12.2, you can do it but it's very annoying to do. At least as far as i'm aware.

I could be wrong or have outdated information, but I'm pretty sure forge hasn't reimplemented in-game configuration yet, so you must edit the file manually.
It's in your 'config' folder, if you can believe it.

just going though and this should help

mod called configured
https://www.curseforge.com/minecraft/mc-mods/configured