I guess you haven't observed the link. It's the advertisement of a person offering his/her service as a freelancer. Fiver is a freelance platform so the guy is just searching for a job. You will probably won't find a free platform for payroll. Maybe there are some but the data security is questionable. Plus, depending on your activity and complexity of wages formula, the free service could not offer such a range of possibilities. There are some companies that would take that for you for a fair price. Or, you can buy a subscription on platforms like https://www.payrollindex.com/outsourced-payroll/ and do it yourself.