It's cute.
But, the reality of the situation is that it is WAY too small for 6 chickens. I fear you have fallen victim to unethical advertising, IMO, and your chickens will suffer for it. If you have no alternative but to use that tiny coop, you should really consider building a much larger
fully secure run attached to it so that you never have to close the pop door. You have no idea how much that will help your situation.
After reading possibly a thousand posts on this type of thing, I feel the number one reason for behavioral issues in flocks is a lack of space. And boy do you have it!
As for the DE, return it if it is unopened. It really serves no useful purpose and can actually cause harm.
I am truly not trying to rain on your parade, just trying to prepare you and hope that you will be able to provide a lot more space for your girls.
Good luck.