For those interested. Linux 64 bit version. At first I thought it did not work. Needed an extra click on the menu shortcut and it can generate error messages.

However FWIW zipped and attached. All-in-one example.

Thank you. Yeah I forgot to mention the double-click problem. But I remember placing G'mic on the main menu earlier and it did the same thing.
The one I compiled yesterday was for 2.8. Tried first on 2.10 but there was lot of deprecated calls.
How do you fix them? I replaced them in the .c file but didn't manage to fix it.

Compiled in a 'buntu 18.04 (VM) Gimp 2.10 and yes, plenty of deprecated call warnings, but they are just warnings not errors. Proving the plugin works with Gimp compatibility, I just ignore them. The plugin is not alone I get plenty warnings from more recent code, gimp_gmic or BIMP for example.

At first, it wouldn't work no matter how many times it was clicked. It was grayed out. I then realized I had to remove the Alpha Channel first. Then it worked.

How to move this to Filters > Edge-Detect?

There is actually a "To Do" comment in the code for that, so recompiled. Try the attached, find in Filters -> Edge-Detect -> Canny