If these are your first batch of chickens in new facilities and property (no chickens before), then you don't really need to do anything yet.
Most birds don't dust until they have feathers. I think the earliest I've seen dusting is at 8 to 10 weeks. I normally don't see dusting behavior until they are adults.
So unless you see mites/lice, I wouldn't worry about it quite yet....not until they get feathers. You can put a box out if you like.
However, I have concerns with DE. It is known irritant to lungs (the small crushed silica actually produce razor like abrasions). Bird lungs are delicate, even more so with young chicks.
I've not seen solid evidence that DE is that effective. I personally prefer to use permethrin dust, which can be applied to chicks at a young age if you see evidence of infestation.
Otherwise, provide a box out for when they are ready.
LofMc