u/IndividualVacation78

I have a question and I am not 100% sure on it.

My parent works for a small company. They aren't feeling well today and they are scheduled to work tomorrow but want to take the day off to recover. They have earned sick time and think they are only going to be out for the day but there employer is telling them they need to provide a doctors note to take the day off. Per the company handbook, there is nothing stated that they need to provide a doctors note to use earned sick time. What can my parent do or say? I feel like this isn't right, as I've only ever been required to bring in a doctors note when I was out for 3+ consecutive days when I was sick at other companies.