In My Rush To Play, I Didn't Notice The Left-Right Mouse Setup

Is there a way to reset the mouse’s L-Click/R-Click commands. In game that shows as locked and can’t be reversed.

I will admit I probably didn’t notice and I should change those two around. My L-Click finger is already shot to hell.

There is.
Setting->Hotkeys-> Basic controls.
There is a box you can check that says “Attack with right click” uncheck it and it should change the attack to left