PRC Tie Back is not calling the extension PA_CC_AP_INV_CLIENT_EXTN

Hi

I am trying to utilize the extension PA_CC_AP_INV_CLIENT_EXTN for Project Intercompany Invoices between LEs/OUs.

I have kept few debug messages and enabled PA Debug Log at User level. However log file of the PRC Tie Back is not showing those messages. I am thinking the extension is not being called.

What i am trying to do is to utilize the procedure 'override_supplier_site_info' in this package. I want to change the Exchange Rate Type of IC supplier invoice

However i am not sure the Debug messages are not showing up on PRC Tie Back and also the exchange rate type is not having a change on the Supplier Invoice. I havent removed any existing code in client extension. I see this extension is called by Standard package PA_CC_AR_AP_TRANSFER. Is there anything else i need to do to invoke this extension.