does anyone have a simple carrot on a stick detection?

for some reason i cant get this to work like at all, and ive tried so many tutorials and templates, so if anyone could help me that'd be great!
ps: if u have id like to have fungus on a stick in the same datapack and have them do different commands when rightclicking, but i think i can do that myself, but for whatever reason im dumb enough to not be able to do the detection part, version 1.20.1