My manager doesn’t let me leave when I’m supposed to, what can I do about it (USA)

I am supposed to clock out at midnight, and my manager is repeatedly keeping me over an hour after I’m supposed to clock out every night, because I supposedly have jobs to do before I can leave. For example last night I was in the second window for about an hour and a half and then she made me do stock for another hour and a half, which meant I didn’t leave work until after 1am. Is she allowed to do this??? I can’t imagine that she can force me to be at work longer than I’m supposed to, with the threat of writing me up for leaving on time??

Edit: I’ve messaged the store manager about it. Some extra info is that I work 35 hours a week, and being made to stay an extra hour every day means I am working 40 hours without benefits. Due to personal circumstances I put in my two weeks a few days ago, not because of this, so instead of asking for full time benefits I’ve only asked that I can just leave on time.

Edit 2: I had no customers and I had restocked sauces as asked so I left a minute after midnight despite my manager threatening to write me up. I had been in the window constantly for 2 hours with no chance to get out. We will see what happens tomorrow

Edit 3: Success!! Manager gave me a small list and took over window, and I left on time. Thank you all for your input and advice