https://userapps.support.sap.com/sap/support/knowledge/en/2149315
2149315 - BAPI_INCOMINGINVOICE_CREATE and BAPI_INCOMINGINVOICE_CREATE1: custom fields EXTENSIONIN...
It is necessary to map and update custom-specific fields with the BAPI_INCOMINGINVOICE_CREATE or BAPI_INCOMINGINVOICE_CREATE1 by filling the structures...
custom fieldsbapicreate