can't get automatic discount code when querying order in graphql

[jklue]

This query does not give me the automatic discount code that was applied on the order...

{
  order(id: "gid://shopify/Order/3881781461190") {
    discountCode
  }
}

But you can see there was a discount applied...

 

discountCode seems to give me text that was added to a discount on a manual order entry via the shopify admin, but not on codes in the cart.