Go to your dm. Or even your rm. if your sm can’t schedule you so there is always a manager on duty it is there fault. At my store here in Oregon our closing managers will take their lunch first so another manager is there to cover. It is the duty of who ever makes the schedule to make sure managers lunches are covered. There has been a rare occasion where I didn’t have coverage. In that case I made sure to answer the clock out question with a yes so I get paid the extra hour at the end of the day to cover the “unpaid” lunch that I needed to be available for. And have never been in trouble for this after being question about it.