I made customizations to the Shipment and SOShipLineSplit screens in Classic UI. Thanks to this post
https://community.acumatica.com/develop-customizations-288/modern-ui-adding-custom-fields-to-line-splitting-grid-so302000-using-shared-templates-34079?tid=34079&fid=288
I can now customize the line grid of the ShipmentLineSplit. But how can I customize the header section of the SOShipLineSplit panel? My requirement is to display the total quantity of the current split lines in a dedicated field.
I successfully implemented this in Classic UI before, but I don't know how to migrate it to the new Modern UI — specifically, how to display my existing field on the new Modern UI page. The issue I'm facing is that in my old customization project, the Usrshippedqty field is defined in the SOShipment DAC. How can I display this field on the SOShipLineSplit panel in the new Modern UI?

My customization projects are attached. 1 is with modern file, the other is without modern file
By the way, the Modern UI npm build completes successfully, but publishing throws an error. However, this is a separate issue that I am seeking help for in another post. Please guide me on how to add this field here.

