Hello, Bagya. 

Let's work together and ensure that the SKU column reflects on your Item Listing report and on the exported Excel file. 

For the missing SKU column in the Item Listing report, it looks like it's not yet added to the report, which is why it isn't reflecting on the report. 

In this case, we'll want to customize the Item Listing report and add the SKU column. Here's how to do it:

1. Generate the Item Listing report.
2. On the report view, click the Customize Report button.
3. Go to the Display tab.
4. Search for SKU (or whatever label entered for the custom field) under the COLUMNS field.
5. Check the column, then hit OK.

This works if you've added a custom field for the SKU numbers. If you're using a different field, such as the Manufacturer's Part Number (abbreviated as MPN for the column) field, add it to the report instead. 

Just to clarify and address the exported Excel file issue, is the column still not showing after adding it? It's likely placed at the near end of the report. We can scroll to the right-most part of the exported report to see it. 

Need more help customizing your reports, let's take a look at this article for details: Customize reports in QuickBooks Desktop. 

Want to learn more about using the Sales Order Fulfillment Worksheet feature for your sales and inventory? Check out this article for more details: Use the Sales Order Fulfillment Worksheet. 

Let me know if you have more concerns about the reports or your items list. I'm always here to help. If you happen to come across any difficulties while managing your entries or data, add the details to your reply and I'll assist you.