Overpayment letter from the unemployment office, electrician's helper here

I received a letter saying I was overpaid about $1200 on my claim. I am in San Diego, in case local advice matters. The letter mentions an appeal window and a repayment plan. Are payment plans possible?

Collect your pay stubs and certification records for the weeks they name. Mine showed the error was a date mix-up.

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.