Hi,
you may leave it blank or insert any minima related to any let down procedure in use as you can't be 100% sure that you'll get the approval to fly the visual approach (unless there are no published procedures obviously). Whatever you want to do it's technique anyway. Some people leave it blank, some insert 500 or 1000 ft to have a wake up call from the auto callout function to check the stabilisation. None of this is required anyway and may be misleading if you don't brief it correctly.
Enjoy.