Can't map left mouse button to Controller

[Kornelious]

Hi, I'm using a PS4 controller running through the DS4Windows program. The controller connected and works fine but for some reason I can't map the left mouse button to the controller, it's just grayed out and has nothing set to it...The left mouse button is used to confirm a lot of things in the game, and I can't do much without it. Sorry if this is a stupid question, but I can't really play the game with a controller without figuring this out.