In this FICO configuration activity you are able to define accounts for account receivable items revaluation.
Transaction: S_ALR_87002693
IMG Path: Financial Accounting (New) -> Accounts Receivable and Accounts Payable -> Business Transactions -> Closing -> Valuate -> Valuations -> Define Value Adjustment Key
Table: T044G, T030U, T030B
On the main screen you see a list of procedures. Double click on flat-rate individual value adjustment.
Before proceeding, choose chart of accounts.
On the next screen you could maintain your GL accounts according to your needs.
If you choose “Posting Key” button on the above screen you will see and be able to maintain debit and credit posting keys.