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

I picked up part-time shifts as a production planner and I am confused about how to report them. This is my first time dealing with any of this. The form asks for gross earnings, which I do not see until later. Did anyone get an overpayment notice from a mistake?

Keep everything in writing and save the confirmation numbers. It saved me later.

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