Hi Artur,
Thanks for reaching out. Unfortunately, it is currently not supported to retrieve the country information of a campaign from the keyword_view report in the Google Ads API. However, you would be able to retrieve this information from the geographic_view report by retrieving the resource field geographic_view.country_criterion_id. Please let me know if you have any further questions or concerns.
Thanks and Regards,
Xiaoming, Google Ads API Team