I cannot create a custom script for Delivery Note Item

I am unable to create a Custom Script on a Delivery Note Item.

The Doctype “Delivery Note Item” does not show on the list of available doctypes on the Custom Script form.

How can I add a script to the Delivery Note Item table?

chose delivery note ,
then write the code for filed name linked with Delivery Note Item for example :

frappe.ui.form.on("Sales Invoice Item", "batch_no", function(frm, cdt, cdn) {
    var d = locals[cdt][cdn];
        frappe.db.get_value("Batch", {"name": d.batch_no}, "expiry_date", function(value) {
            d.expiry_date = value.expiry_date;