Overpayment letter from the unemployment office, medical assistant here

The agency says I reported earnings incorrectly, but I think I followed the instructions. This is my first time dealing with any of this. I did not notice any errors at the time. Has anyone disputed one of these?

Read the letter for the appeal deadline and act on it, even if you think you will end up repaying. Then ask about a payment plan.

I asked for a waiver and a plan in the same call, and they gave me both forms. It was less scary than I expected.