TrYJoRdY

Hello, I'm new here so hello, I have a question about conflicting controls in a modpack, I play alot of "Attack of the b-team" and I saw that they are using a button in the settting that's called "Conflicting controls" wich show like it says all the buttons of your mods that are conflicting with eachother. Now is my question does anybody know how they added that button? Is it just a mod they used? Or should i program it on my own? Thanks