How do I set up an action to email all users with a certain role? I'm using Rules 7.x-2.6 and the way it works has changed a bit since I last saw.

I have a rule as follows:

EVENT
A node has been flagged, under "Report content"

CONDITIONS
None

ACTIONS
Send mail to [site:mail]


However, I'd like to, instead of sending directly to [site:mail], send an email to all users flagged with an "admin" role. 

Now I know that I'll need to provide a loop do so, but my sticking point is generating the list of users to pass to the loop. So far, I have attempted to add a new action: 

"Fetch entity by property"
Entity type: User
Property: User roles
Value: admin


But this doesn't seem to give me what I want in data selection, when passing it to the loop. Can someone recommend what they would set here?
I have "Send mail to all users of a role" available when I add an action.


edit rule
click add action
Under system section select "Send mail to all users of a role"
Select role and save