Godot Community

I do my training through Godot docs. And the training there is based on the current version. I don't know if it is related to the problem, but I am using C#. I think I set some things wrong.

While the signal I added to Godot is automatically reflected in my code, it gives me a warning that a connection cannot be established. Also, while the man whose training I watched has a green icon next to the signal code, this icon does not appear for me. I would be glad if you help.