Refinement of the action Calculate and write a value to an additional field

There is an action Calculate and write a value to an additional field It has the ability to calculate the amount of incoming / outgoing payments by payment categories https://prnt.sc/vjw56g It is necessary to add the ability to calculate payments by additional fields by payment categories. There are additional payment fields https://prnt.sc/vjw745 You need to make a variable for example [finance_category_1_summaplatezhaveur1] that will sum up the additional payment fields of the category There should be such variables for each additional payment field. Example: There are 3 payments per process per payment category Payment from client: 1 incoming payment - 100 UAH. The value in the additional field is 90 2 payment incoming - 200 UAH. The value in the additional field is 190 3 outgoing payment - 100 UAH. The value in the additional field is 90 The total variable should calculate the sum for these fields: 90+190-90=190 How long will such a revision take?