Hi Berto,
Thank you for reaching out. In terms of the headline fields, it looks like those are not available in AdWords API. I have submitted a feature request on your behalf so please keep an eye on our
Developer Blog for information on future releases.
For the Display URL, it is required when creating the ad in the UI and API. If you try and create the Ad in the UI, you will notice that the Display URL is pre-populated.
Regards,
Mitchell
Google Ads API Team

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