IHC Centre - DIRDEB IDOC: ALE inbound methods for the process code

Hi SAPer,

We are looking to process debit memos through IHC Centre using IDOC (message type DIRDEB) in the similar way as payments.

However, The status of the IDOC error is 51 and the error states "The function module IHC_APPL_PAYEXT_INPUT_IHC and the application object type which were determined are not valid for this IDoc.

Would any of you advise which ALE inbound method need to be assigned for DIRDEB Message for IHC?

Thanks in advance

taro