ID Notify is a service you might have subscribed to as an add-on benefit, along with Audit Defense and some other things. It's not run by Turbotax. You have to log in directly to see what they have to say.
Having your email address on the "dark web" sounds scary but is normally not a problem by itself, it just might mean you get a little more spam than usual. I would be more concerned about passwords, credit card and birth dates.
