Help with rollup sheet structure and formulas

We have contractors that we pay every 2 weeks. I created a form for them to upload invoice info into. I also created a report that pulls the individual invoice totals. What i want to create is a rollup sheet that will give me a total of that week's invoices for a given contractor. So for instance...Total invoiced amount for John Smith from June 24, 2019-July 5, 2019...