UnityPluginLoad never called on iOS, Is it just broken?

I looked at the [low level native interfaces][1] and built a iOS plugin (static lib), exporting the required functions described in the Link. There is no Problem calling functions from script manually, it's just that UnityPluginLoad is not working as described. Am I missing something? or is it just not working AND not documented?? [1]: https://docs.unity3d.com/Manual/NativePluginInterface.html