Hello,
Thank you for writing to us. You can find the details on how to create smart shopping ads here. The Ad will have a field called shopping_smart_ad which can be set to ShoppingSmartAdInfo. Please refer to the below code snippet for reference. You will need to pass the ShoppingSmartAdInfo object in your ad builder and this way there will be no impact on the remarketing ads. Currently, we do not have any methods to add text, logos or marketing images to the ad via API. A feature request regarding your concern is already created internally within our team. Please keep an eye on our blog post for future updates and announcements related to this.
ShoppingSmartAdInfo shoppingSmartAdInfo = ShoppingSmartAdInfo.newBuilder().build();
Ad ad = Ad.newBuilder().setShoppingSmartAd(shoppingSmartAdInfo).build();
Regards,
Nikisha Patel, Google Ads API Team