Downloaded it and the demo project works great on Godot 4.3 (minus a missing texture on the log) but I can't work out how to import it in to my own scene?
Viewing post in Stylized 3D Fire and Smoke VFX Godot comments
Glad that it works well in 4.3!
If you simply move all the folders (Models, Scenes, Shaders) to your project, it should work. You can find the Fire and Smoke scenes in the "Scenes" folder. There is nothing complicated in it.
You can also watch this video on how the project was set up: Stylized 3D Fire and Smoke in Godot