The problem is that one does not have focus anymore. I can see that and have tried ALT+R (which would work if focus were on the notification, but it's not). One must get focus back to the notification and ALT+D, followed by SHIFT+TAB (sometimes more than once) will get you there.
I'll give that a try. Windows generally gives "many roads to Rome" and I'm sure this is no exception.
Brian - Windows 10 Home, 64-Bit, Version 1803, Build 17134
A great deal of intelligence can be invested in ignorance when the need for illusion is deep.
~ Saul Bellow, To Jerusalem and Back