I'm exporting products and their variants from one odoo instance to another (18->19).

I have managed to figure out how to export and import products together with attributes and values which then creates the correct variants. 

I use the attributes and values external ID, so the import is as correct as it can get.

The problems is that there is data in the variants which i want to export such as internal reference for each variant.

I'm unable to do this. I guess it's not easy because the variants needs to be created first when they are imported then proper data needs to be imported to each variant.

The problem is that i cannot even export the External ID of each variant so I'm not sure how to do this if i don't have External ID for each variant. Is this possible?

How can I export and import variant data?