Reporting part-time earnings while on benefits - 9 months and counting

I picked up part-time shifts as an accountant and I am confused about how to report them. It has been weighing on me all week. The form asks for gross earnings, which I do not see until later. Did anyone get an overpayment notice from a mistake?

The claimant handbook has worked examples for part-time pay. Mine was clearer than the phone line.