How to post a photo to a page with a tagged Product via Graph API v12.0?

Question

We have a Facebook Shop and a Business Page, and are using Facebook Graph API to create Photo posts on the Business Page using the Javascript SDK running in a browser. How do you include the tagged Product in the Create Photo request?

https://developers.facebook.com/docs/graph-api/reference/photo/ mentions a tags field you can pass which is described as "Tags on this photo", however it has a tag_uid "The user_id of the tagged person". Is this tags field how you are supposed to tag a product?

A similar question from 2017 was not answered and is so old I thought I'd post a new one: Publish new facebook post with tagged product

What we've tried so far

To get a list of our products, we can use GET ${businessId}/owned_product_catalogs to retrieve a list of catalogs, and then GET ${productCatId/products with a filter: '{"custom_label_0":{"eq":"something_to_match"}}' to get a specific product in the catalog. So now we have the ID of a product we want to tag e.g. "4378279312278116". (we happen to use custom_label_x fields meaningfully, of course the filter could have been something else but this works for us)

To create the photo post, we can POST /${account.id}/photos with a payload like:

{ caption: 'Test caption',
  url: image_url,
  access_token: account.access_token,
  tags: [
    {
      tag_uid: "4378279312278116",
      tag_text: 'Test tag',
      x: 10, y: 10
    }
  ]
}

This request completes OK and does post the photo, but nothing is tagged on it when we view it on our page.

Trying to read the photo with GET ${photo_id} only returns basic infomation fields created_time, id, name. I can't see how to read further fields on the photo object to check if the tags data was associated with it correctly.

Any advice please?