This is an example that shows a minimum implementation of a native audio plugin for Unity.
Although this example might be helpful to grasp the basic idea of Unity's native audio plugin, it doesn't deep dive into further topics. For more detailed examples, please check the official examples repository available on BitBucket.
Just generating and sending a sine wave signal to the destination port.
Although implementing a native audio plugin is pretty straightforward, there is one common pitfall that should be aware of.
... the current convention is to prefix the DLL of the plugin “audioplugin” (case insensitive) so that the system can detect this and add it to a list of plugins that will automatically be loaded at start.
So, if you can't find your plugin in the audio effect drop-down list, please check if the filename of the plugin is following this convention.