Hi,
Thank you for reaching out to the Google Ads API support team.
Based on the provided information , it appears that you cannot create an Asset Group without including the minimum required assets via the Google Ads API. Kindly note that each AssetGroup in a Performance Max campaign requires an initial minimum set of assets. These could be existing assets used in other campaigns or new assets specifically for an AssetGroup in a Performance Max campaign. I would recommend you to check this
Asset Requirements documentation for more information.
