Welcome to the Community, @TracyC2.

There's no need to convert to QuickBooks Online (QBO) to use the Warehouse Manager feature. All you need to do is to install QuickBooks Desktop (QBDT) mobile app on a supported mobile barcode scanner or an android device. Them, pair it with your QBDT company file.

Once connected, you may now use the scanner, by setting up warehouse users (pickers). You may refer to the article you've shared above for the detailed steps on how to go about it. 

For tips and other resources, I recommend visiting our website for future reference: Self-help articles.

Don't hesitate to post again or leave a comment in this thread if you have any additional concerns or questions. I'll be more than happy to help. Have a good one!