Backerupper Standard does not show Merge option

My version of Backerupper Standard is not showing the Merge Images option under Utilities.  I see only Check Image, Create Bootable Media, Explore Image, and AOMEI PXE Boot tool.

I need to merge a bunch of images to save space and am feeling frustrated.  I'm sure it's a PEBKAC error, but have been undable to diagnose it.

Thanks for any help.