I think it'd be possible to build a client which would GET /objects/shoppinglist from the grocy API[0] to retrieve the shopping list items, which currently have the following schema:

  {
    id integer
    product_id integer
    note string
    amount number
    row_created_timestamp string
  }

Do you know if there are clients for Instacart (and/or other food delivery services) available?

[0] - https://demo.grocy.info/api