Proper shippingDetails structured data for products that don't ship?

A gift card product my client sells does not require shipping. When we excluded the "shippingDetails" field in our structured data, Google Search Console flagged it as an issue. After seeking help online without success, I consulted ChatGPT which provided a potential solution. However, Google Search Console rejected this as an "invalid object type." Is there an official method to inform Google that a product does not require shipping?

The “shippingDetails” field is mandatory for product structured data, regardless of whether the product requires physical shipping. To address this, you can use the shipping property within the “shippingDetails” object and set it to false. This indicates that the product does not require shipping.

Here’s an example:

{
  "@type": "Product",
  "name": "Gift Card",
  "description": "Gift card for [store name]",
  "image": "https://example.com/gift-card.jpg",
  "offers": {
    "@type": "Offer",
    "priceCurrency": "USD",
    "price": "10.00",
    "availability": "https://schema.org/InStock",
    "shippingDetails": {
      "shipping": false
    }
  }
}

By setting “shipping” to “false” in the “shippingDetails” object, you explicitly tell Google that the product doesn’t require physical shipping. This should resolve the Google Search Console issue and prevent the product from being flagged for missing shipping details.