Passive income definitely requires management. What's most important is that you're not obligated to be somewhere or do something at the certain moment. For example, you can be sick for a week and not do anything in that period but you would still be earning money and then you can continue.

Let say you wrote a book or you're selling some kind of your own product online. You will definitely have to either do marketing on your own on manage the people you outsource to do the management for you so that money doesn't stop coming due to lack of marketing.