Hi there. I’m building a plugin right now.
You have to add “PluginNameFolder/Public” to that list.
In fact, the plugin must have several folders in the source folder. At least one, for the main module. I have two in mine, for example. Each of them contains the build.cs file.
Remember that you can’t use anything from the Private folder in the Public. So if you create something to be public in your plugin, then everything it includes should be public too.
Cheers