Unable to use any plugin for Mac OS X in Unity Stadnalone/editor. 2020.1

Hi, I am unable to make any plugin work with Unity in Mac for Mac Os X.

What I am trying to do is have a function that returns an int from native code and show that on screen.
However I get the exception EntryPointNotFound for this function.

unityDeviceMac.h
//////////////////////////

//#import <Metal/Metal.h>

extern "C" {
int TestFoo();
// id<MTLDevice> GetUnityNativeDevice();
}

unityDeviceMac.cpp
//////////////////////////

#import "unityDeviceMac.h"

int TestFoo()
{
return 999;
}
/*
id<MTLDevice> GetUnityNativeDevice()
{
return UnityGetMetalDevice();
}*/

But now I see that "__Internal" only make sense for iOS, not Os X.
So how do I import this in OSX? Standalone and editor?

I know you need to build an OSX plugin as a bundle.
I was able to do that, but didn't make it work as well.

 

I was having similar issues on Unity 2021.3.

Finally I built the plugin as a bundle and when I build for macOS the plugin is found and runs.

But in the Editor, its not found. I have no idea why. Anyway for me having it work in the build is "good enough", it was just an annoying waste of time that it did not work in the editor.