issue HCM Data Loader (Worker Templates)

Summary

When I try to update new workers with spreadsheet, the process fails

Content

Hi,

I've to insert for the first time new workers inside the organization. I can't insert them manually because I've to insert 73 records, so I've tried to use HCM Data Loader (Worker Spreadsheet Template), but the speadsheet doesn't work because I've to insert "Person number". In HCM Enterprise Information "Person Number Generation Method" is set to "Automatic Prior to Submission".

Have I to do some other set up? Or Have I to use some other method to insert my workers? 

Thanks

Federica