How to add an Item record custom field to SCM Mobile page

Hello,

I've been trying to figure out how to add a message to our Picking process on the mobile device but stuck on setting up the message.

I'd like to show a message on the Item scan page stored in this field:

I have cloned this process: NSWMS_singleOrder_salesOrder_Picking_1

I added a Page Element to singleOrderPicking_itemScan_1. I set it up as a Dynamic Text with Label "Item Packing Instructions" and the message is defined as {state:dataRecord:item:custitem_packship_item_packinstruction}}

This is where I'm confused.. I'm not sure how to create valid messages or add data to auxParams (if that's what I should be using).