How to make player swing item?

I'm trying to make a weapon dual wieldable, that is, when the player swings it, if they are holding the same weapon in their other hand, it swings the off hand as well. I tried this:

 https://drive.google.com/file/d/18zklXMx6V_lJIrjA_YlSR3_W4cuVji3X/view?usp=sharing

But for some reason it isn't working. How can I make this work?