In 18.0.1 the audiogram setup isn't on that screen, it's through the "Custom Audio Setup" button. If you select that, then "Continue" you get to a screen that says "Add Audiogram". It's not in the red circled area, though that may have been where it was under previous versions of iOS.
EDIT: I added some (faked) audiogram data to the Health app just to see how that appeared. It also does not show up on that initial screen, you still have to select the "Custom Audio Setup" button and then you can select an audiogram stored in Health. This is not a change new to 18.1, though again maybe prior to 18 it appeared on that initial screen.
