Was any such request sent? By whom? I would not be surprised if Muriel Bowser requested more Guard troops. I don't know how big the D.C. Guard is or for what it is trained, but Bowser would probably be happy to provide a fig leaf for this kind of action. But that would not be a request from "U.S. National Guard officials;" it would be a request from the DC government for assistance from other states.
Technically DC does not have any authority since it is a federal district (at least for now).