Data Integration Hub: Work order Header - Importing Item code is mandatory

When uploading a work order, the item code is mandatory map, 

However, when creating it manually, it is not mandatory. 

The field is not primary, but still the import is blocked if the item code is not mapped. 

It is explained in the documentation: it is mandatory to map item on Work order header upload in the data integration hub:

We will improve this functionality and maintain consistence of both processes in the future.