Disable Item Line fields in Workflow action script

The below sample script can be used to disable the item sublist fields in transaction records in Workflow action script

const onAction = (scriptContext) => {
            try{
                if (scriptContext.type == 'edit')
                {
                    let record = scriptContext.newRecord;
                    // Add the line fields that need to be disabled to an array
             
       let itemFieldIds = ["quantity", "amount", "rate", "price"];
                    let form = scriptContext.form;
                    // Disable fields
                    for (let i = 0; i < itemFieldIds.length; i++)
                    {
                        form.getSublist({
                            id: 'item'
                        }).getField({
                            id: itemFieldIds[i]
                        }).updateDisplayType({
                            displayType: serverWidget.FieldDisplayType.DISABLED
                        });
                    }
                }
            } catch (e) {
                log.error("error @ beforeLoad", e);
            }
        }
        return {onAction};
    });