How to sort a field in a nested addon

Hi,

I am trying to sort a field in a nested addon - as below

I want to sort this by event_sequence. I have watched the video here. This is my function -

Xanoscript -

Copy

query getOrderDetails_0 verb=GET {
  api_group = "shipogogo"

  input {
    int order_id?
  }

  stack {
    db.query sgogoOrders {
      where = $db.sgogoOrders.id == $input.order_id
      return = {type: "list"}
      addon = [
        {
          name : "orders_to_shipments"
          input: {sgogoorders_id: $output.id}
          addon: [
            {
              name : "shipments_to_events"
              input: {sgogoshipments_id: $output.id}
              as   : "_shipments_to_events"
            }
            {
              name : "shipments_to_couriers"
              input: {sgogoCouriers_id: $output.sgogocouriers_id}
              as   : "_shipments_to_couriers"
            }
          ]
          as   : "_orders_to_shipments"
        }
      ]
    } as $sgogoOrders1
  
    var $sort_sequence {
      value = $sgogoOrders1
        |set:$sgogoOrders1._orders_to_shipments._shipments_to_events:"$$|sort:event_sequence"
    }
  }

  response = $sgogoOrders1
}

and here is the error

I also tried a sort -

Copy

query getOrderDetails_0 verb=GET {
  api_group = "shipogogo"

  input {
    int order_id?
  }

  stack {
    db.query sgogoOrders {
      where = $db.sgogoOrders.id == $input.order_id
      return = {type: "list"}
      addon = [
        {
          name : "orders_to_shipments"
          input: {sgogoorders_id: $output.id}
          addon: [
            {
              name : "shipments_to_events"
              input: {sgogoshipments_id: $output.id}
              as   : "_shipments_to_events"
            }
            {
              name : "shipments_to_couriers"
              input: {sgogoCouriers_id: $output.sgogocouriers_id}
              as   : "_shipments_to_couriers"
            }
          ]
          as   : "_orders_to_shipments"
        }
      ]
    } as $sgogoOrders1
  
    !var $sort_sequence {
      value = $sgogoOrders1
        |set:$sgogoOrders1._orders_to_shipments._shipments_to_events:"$$|sort:event_sequence"
    }
  
    var $sort_sequence {
      value = $sgogoOrders1
        |sort:$sgogoOrders1._orders_to_shipments._shipments_to_events.event_sequence:"itext":true
    }
  }

  response = $sgogoOrders1
}

but got this error -

I would appreciate any assistance.

Thanks

Steve