Hi, I believe you are all familiar with the 2D game engine gdevelop. I’m looking for a 3D game engine that has a code-free and easy to use scripting method like gdevelop. Do you know one?
I do not have a best answer. The Unreal Engine has Blueprints to define complex logic without writing “traditional source code in a text editor” – although using Blueprints for non-trivial applications will be equivalent to just “coding, but using visual things”, IMHO. I mean, as soon as you try to do something non-standard, things are difficult in all game engines :), whether you write “traditional source code” or drag around boxes in Blueprints.
As you posted this within Castle Game Engine forum, you probably know that CGE supports both 3D and 2D games 
See our features on https://castle-engine.io/ and linked pages. But admittedly CGE is not a “code-free” game engine. While you can do more and more things visually, using the new CGE editor (and I do expect that soon you will be able to even design a simple FPS game with just clicking) but there’s just a limit to what you can without any coding at all.
If you decide to give CGE a shot anyway (knowing that at some point you will hit a wall “to do this, you just have to write code”) please go for it, and write your conclusions. I am interested in how the CGE editor is useful for non-coders. We know we have a lot of things to add there, but we know that extending editor (effectively extending “what one can do without coding”) will be our focus for a long time.