Please note that you are likely going to be waiting eternity. While nothing is impossible, GDevelop’s focus has been stated to be 2D, with no plans nor goals to add 3D.
As Arthuro mentioned, CopperCube is going to be your closest bet. It isn’t open source but it is free, and includes a visual scripting system that is pretty easy to get set up and use. That said, No other engine uses GDevelop’s event system, even Construct 3 isn’t an exact match.
Please note there are numerous topics on 3D and 3D engines, and the above answers are the same in those as well, so please search in the future before making a new thread.