Hi itsupport-micheleperesso ,
I've just tested the insert process, including the ID column with an empty value and the product was imported properly.
Please open a private ticket here and include the CSV file you're trying to import. Please also attach the template you use to import (if it's a custom template).
You can read here how to export and attach custom templates from your site.
As for the barcode field, it is not included in our default product template, but you can add it when creating a new custom template. Please check the image below.

You can read about creating custom templates in this article.
Best Regards,
José Andrés