Please try:
Financial Accounting>>Account Payable/Acct Receivable>>Business Trans.
>>Outgoing payments>>Automatic Outgoing payments>>Payment media>>DME>> Define Instruction keys (On the master data - Use Instructions Key on Payment Transactions tab of general data segment)
Financial Accounting>>Account Payable/Acct Receivable>>Business Trans.
>>Outgoing payments>>Automatic Outgoing payments>>Payment media>>DME>> Define Instruction s for Payment Transactions (need to enter the instructions key on the payment tab of invoice, for example FB60). If the field status of the invoices are not adjusted, please open up the field instruction key.