yep change all three to 6 - that will give you perimeters made of 2.4 mm of solid plastic and top and bottoms of 1.8mm.
so perimeters and top and bottom layers.
resolution needs to be 'low (faster)'
Combine infill should be every layer - if it will let you.
Otherwise it offsets every other layer - which looks pretty, but is nowhere near as strong.

Have to download a copy of that software and have a play with it.

I've just bought an electroplating with copper kit to make some of my prints super strong. But I've used pla for some pretty tough items.