How can I pin a manually-installed app to the Cinnamon panel?

I'm using Devuan Daedalus, with the Cinnamon desktop environment, v5.6.7. I've installed an app to /foo/myapp on my system, and have even created a start menu entry for it via the menu editor. Now, I would like to have the icon/button for this app pinned to my panel - like I can do for many other apps (e.g. Firefox, Nemo, Quassel etc.), with right-click menu on the running app's panel button. Unfortunately - I don't get this option on the right-click menu for my new app. Why is the 'pin to panel' menu entry missing? Is there something I need to do to "bless" this application so that I may pin it?