Enters text(in this case, password) in the default selected input field, and presses default selected button in the security prompt.

Tell SecurityAgent to input password and press Enter when process SecurityAgent exists

set appPass to "PASSWORD" as text

tell application "System Events"
	delay 0.5
	repeat until exists process "SecurityAgent"
		delay 0.5
	end repeat
	tell process "SecurityAgent"
		# writes variable in default selected inputfield(in my case its the password field)
		keystroke appPass
		# sends "Enter" command to default selected button(in my case "Allow")
		key code 36
	end tell
end tell