I'm using an AppImage program (Ripcord). I used appimaged to generate the desktop files, and it successfully appears in the Budgie Menu. I can launch Ripcord through the menu, but when it is launched and I right click on the Icon Task List, the star button to pin it does not appear.
Here is the desktop file that was created:
I'm not quite familiar with these files as they're usually automatically generated, so I don't know what prevents Budgie from recognizing the app to pin it (that is, if the issue is with the file in the first place).