edit option for salesman

It is a big problem that the salesman can edit old bills and add that the money was received. The admin should give an alert message if the bills are edited a day ago, or they should not be able to be edited except on that day. In places where there is a lot of sales, if he edit and add that the money was received on the day the bill was made after a few days, it will not be understood by admin. The salesman will also take the money