Write a script and implement it on a ready-made platform

Create a program for accounting for the cost of subsidies. The grant is issued to a specific person and a card is assigned to him.
The subsidy is awarded every day and burns down at the end of the day if it is not used.
The employee comes with this card with a subsidy to the dining room and takes whatever he wants. If the amount of his check is more than the subsidy, he pays in cash or with his bank card. If the amount of his check is less than the grant, then part of the grant is written off, and the rest of the donation must be remembered by the system and it will either burn down at the end of the day, or he will come again during the day and buy something else with it.
The system itself must calculate the amount of the surcharge to the subsidy, so that the employee at the cash register does not get the calculator.
Once every 2 weeks, it should be possible to form a report on each card with a grant and how much money he spent on all employees with this grant with one file. The company pays us this money by non-cash payment.