First,,,,, chickens do not need to take a bath each day!!!. You can try and make a covered bath enclosure, Not sure chickens will favor such.

If it is just a covered portion in your run, with open sides, I think that would be preferred.
Use potting soil that is not enhanced with fertilizers as the top choice for dust bath medium. (chosen by my chickens when no ashes present) My chickens LUV


ashes from my campfire pit. I have a section of run in sand. They do scratch there, but do not choose to bathe there.

They prefer earth soil when in run.
I don't think DE is necessary. I am careful using DE, and only place a thin layer as base in the coop floor. Then a thicker layer 1/2 inch or so of Sweet PDZ, on top of that. Followed by a generous layer of hay.
Read the cautions on DE. Not good to breathe the dust for humans. I always used a mask, even before Covid came to being.
(the 2 have nothing in common) If DE is bad for my lungs, I suspect it not being very good for chickens lungs ether.
WISHING YOU BEST,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,