File -> Export -> Blackmagic Image Export greyed out

I have the Blackmagic desktop video software installed on my Windows 10 machine and use it for displaying video from DaVinci Resolve, Adobe After Effects, etc. to my Flanders DM240 monitor via a Decklink card.  I see that the Decklink Import-Export plugin is installed in my Photoshop Plug-ins directory.  I can see Blackmagic Image Export under the Help -> About Plugins and when I sleect it it shows the version of my Blackmagic Video Desktop software (v 12.2.2).  Under File -> Import I can select Blackmagic Image Import... and go through the steps to inport an image (I don't have a video source input connected to the Decklink card, so ultimately that fails, but it works properly). However, when I select File -> Export then entry for Blackmagic Image Export... is greyed out and cannot be selected.

How can I enable Blackmagic Image Export?  I have tried changing some settings in my Blackmagic Desktop Video and restarting Photoshop, all with the same result.

Thanks for any help.  Regards, Paul