Hello Pietro,
Thank you for reaching out. If you are looking to retrieve the affinity categories, 'CUSTOM_INTENT' and 'CUSTOM_AFFINITY' via Google Ads API Beta, you could use the custom_interest resource to retrieve this data. Let us know if you have any additional concerns.
Regards,
Nikisha Patel, Google Ads API Team
Hello Pietro,
Thank you for clarifying this better. To retrieve the full list of user interest criterion via Google Ads API Beta, you could use the user_interest resource where the field user_interest.taxonomy_type will give you the taxonomy type of the user interest. You could use GoogleAdsService.search to retrieve this resource via API. Let us know if you are still having issues.
Regards,
Nikisha Patel, Google Ads API Team