display_url not populating

[INI GlobalOps]

Hi I'm doing a simple query - using google ads api v6:

        SELECT

            campaign.id, 

            ad_group_ad.ad.display_url,

            segments.date

        FROM ad_group_ad

        WHERE segments.date DURING LAST_14_DAYS

        ORDER BY campaign.id

but the api does not return any results:

 campaign {

  resource_name: "customers/xxxxxxxx/campaigns/xxxxxxxxx"

  id: 1111111111

}

ad_group_ad {

  resource_name: "customers/xxxxxxxxx/adGroupAds/xxxxxxxxx~xxxxxxxxxx"

  ad {

    resource_name: "customers/xxxxxxxxx/ads/xxxxxxxxxxx"

  }

}

segments {

  date: "2021-07-05"

}

we are expecting:

ad_group_ad {

  resource_name: "customers/xxxxxxxxx/adGroupAds/xxxxxxxxx~xxxxxxxxxx"

  ad {

    resource_name: "customers/xxxxxxxxx/ads/xxxxxxxxxxx",

    display_url: "www.iamaurl.com"

  }

}

if I send a request for final_urls that DOES return results.

Can you please help diagnose or let me know if i'm doing something stupid?